feat(exam): render template PDFs behind setup canvas

- updateUserPreferences: isDarkMode → colorScheme ('dark'|'light') per
  tldraw 3.6.1 TLUserPreferences type (isDarkMode is read-only computed)
- BaseBoxShapeUtil subclasses: add required indicator() method returning
  bounding rect; fixes non-abstract class missing abstract member error

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/AppRoutes.admin.test.tsx

@@ -31,7 +31,10 @@ vi.mock('./pages/NotFoundPublic', () => ({ default: () => <div>Public Not Found<
 vi.mock('./pages/tldraw/TLDrawCanvas', () => ({ default: () => <div>Public Home</div> }));
 vi.mock('./pages/tldraw/singlePlayerPage', () => ({ default: () => <div>Single Player</div> }));
 vi.mock('./pages/tldraw/multiplayerUser', () => ({ default: () => <div>Multiplayer</div> }));
-vi.mock('./pages/exam', () => ({ ExamDashboardPage: () => <div>Exam Marker</div> }));
+vi.mock('./pages/exam', () => ({
+  ExamDashboardPage: () => <div>Exam Marker</div>,
+  ExamTemplateSetupPage: () => <div>Exam Template Setup</div>,
+}));
 vi.mock('./pages/user/calendarPage', () => ({ default: () => <div>Calendar</div> }));
 vi.mock('./pages/user/settingsPage', () => ({ default: () => <div>Settings</div> }));
 vi.mock('./pages/tldraw/devPlayerPage', () => ({ default: () => <div>TLDraw Dev</div> }));

src/AppRoutes.tsx

@@ -7,7 +7,7 @@ import LoginPage from './pages/auth/loginPage';
 import SignupPage from './pages/auth/signupPage';
 import SinglePlayerPage from './pages/tldraw/singlePlayerPage';
 import MultiplayerUser from './pages/tldraw/multiplayerUser';
-import { ExamDashboardPage } from './pages/exam';
+import { ExamDashboardPage, ExamTemplateSetupPage } from './pages/exam';
 import { ErrorBoundary } from './components/ErrorBoundary';
 import CalendarPage from './pages/user/calendarPage';
 import SettingsPage from './pages/user/settingsPage';
@@ -183,6 +183,7 @@ const AppRoutes: React.FC = () => {
             <Route path="/search" element={<SearxngPage />} />
             <Route path="/teacher-planner" element={<TeacherPlanner />} />
             <Route path="/exam-marker" element={<ErrorBoundary><ExamDashboardPage /></ErrorBoundary>} />
+            <Route path="/exam-marker/:templateId/setup" element={<ErrorBoundary><ExamTemplateSetupPage /></ErrorBoundary>} />
             <Route path="/doc-intelligence/:fileId" element={<CCDocumentIntelligence />} />
             <Route path="/morphic" element={<MorphicPage />} />
             <Route path="/tldraw-dev" element={<TLDrawDevPage />} />

src/pages/exam/ExamDashboardPage.tsx

@@ -1,4 +1,4 @@
-import React, { useCallback, useEffect, useState } from 'react';
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
 import { useNavigate } from 'react-router-dom';
 import {
   Alert,
@@ -22,6 +22,8 @@ import {
 import AddIcon from '@mui/icons-material/Add';
 import ArchiveIcon from '@mui/icons-material/Archive';
 import AssignmentIcon from '@mui/icons-material/Assignment';
+import ContentCopyIcon from '@mui/icons-material/ContentCopy';
+import EditIcon from '@mui/icons-material/Edit';
 
 import { useAuth } from '../../contexts/AuthContext';
 import { examRepository } from '../../services/exam/examRepository';
@@ -34,6 +36,51 @@ const STATUS_COLOR: Record<string, 'default' | 'info' | 'success' | 'warning'> =
   archived: 'default',
 };
 
+const VERSION_SEPARATOR = ' · ';
+const VERSION_RE = /(?:^|\s)[vV](\d+(?:\.\d+)*)$/;
+
+type DialogMode = 'create' | 'edit' | 'duplicate';
+
+type TemplateDialogState = {
+  mode: DialogMode;
+  template?: ExamTemplate;
+} | null;
+
+function splitTemplateTitle(title: string): { name: string; version: string } {
+  const parts = title.split(VERSION_SEPARATOR);
+  const possibleVersion = parts[parts.length - 1]?.trim() ?? '';
+  if (parts.length > 1 && VERSION_RE.test(possibleVersion)) {
+    return { name: parts.slice(0, -1).join(VERSION_SEPARATOR).trim(), version: possibleVersion };
+  }
+  return { name: title, version: 'v1' };
+}
+
+function composeTemplateTitle(name: string, version: string): string {
+  const cleanName = name.trim();
+  const cleanVersion = version.trim();
+  return cleanVersion ? `${cleanName}${VERSION_SEPARATOR}${cleanVersion}` : cleanName;
+}
+
+function nextVersionLabel(version: string): string {
+  const match = version.trim().match(VERSION_RE);
+  if (!match) return 'v2';
+  const segments = match[1].split('.');
+  const last = Number(segments[segments.length - 1]);
+  segments[segments.length - 1] = Number.isFinite(last) ? String(last + 1) : '2';
+  return `v${segments.join('.')}`;
+}
+
+function paperKey(t: ExamTemplate): string {
+  return t.exam_id ?? t.source_file_id ?? t.exam_code ?? t.subject ?? 'custom-paper';
+}
+
+function paperLabel(t: ExamTemplate): string {
+  if (t.exam_code) return t.exam_code;
+  if (t.subject) return t.subject;
+  if (t.source_file_id) return 'Uploaded paper';
+  return 'Custom paper';
+}
+
 const ExamDashboardPage: React.FC = () => {
   const navigate = useNavigate();
   const { bootstrapData } = useAuth();
@@ -43,8 +90,9 @@ const ExamDashboardPage: React.FC = () => {
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
 
-  const [createOpen, setCreateOpen] = useState(false);
-  const [title, setTitle] = useState('');
+  const [dialog, setDialog] = useState<TemplateDialogState>(null);
+  const [templateName, setTemplateName] = useState('');
+  const [version, setVersion] = useState('v1');
   const [subject, setSubject] = useState('');
   const [saving, setSaving] = useState(false);
 
@@ -66,33 +114,99 @@ const ExamDashboardPage: React.FC = () => {
     void load();
   }, [load, instituteId]);
 
-  const handleCreate = async () => {
-    if (!title.trim()) return;
+  const groupedTemplates = useMemo(() => {
+    const groups = new Map<string, { label: string; templates: ExamTemplate[] }>();
+    templates.forEach((template) => {
+      const key = paperKey(template);
+      const existing = groups.get(key);
+      if (existing) {
+        existing.templates.push(template);
+      } else {
+        groups.set(key, { label: paperLabel(template), templates: [template] });
+      }
+    });
+    return Array.from(groups.entries()).map(([key, group]) => ({ key, ...group }));
+  }, [templates]);
+
+  const openCreate = () => {
+    setTemplateName('New template');
+    setVersion('v1');
+    setSubject('');
+    setDialog({ mode: 'create' });
+  };
+
+  const openEdit = (template: ExamTemplate, ev: React.MouseEvent) => {
+    ev.stopPropagation();
+    const parsed = splitTemplateTitle(template.title);
+    setTemplateName(parsed.name);
+    setVersion(parsed.version);
+    setSubject(template.subject ?? '');
+    setDialog({ mode: 'edit', template });
+  };
+
+  const openDuplicate = (template: ExamTemplate, ev: React.MouseEvent) => {
+    ev.stopPropagation();
+    const parsed = splitTemplateTitle(template.title);
+    setTemplateName(parsed.name);
+    setVersion(nextVersionLabel(parsed.version));
+    setSubject(template.subject ?? '');
+    setDialog({ mode: 'duplicate', template });
+  };
+
+  const closeDialog = () => {
+    if (!saving) setDialog(null);
+  };
+
+  const handleSaveDialog = async () => {
+    if (!dialog || !templateName.trim()) return;
+    const title = composeTemplateTitle(templateName, version);
     setSaving(true);
     try {
+      if (dialog.mode === 'create') {
         const created = await examRepository.createTemplate({
-        title: title.trim(),
+          title,
           subject: subject.trim() || undefined,
           institute_id: instituteId,
         });
-      setCreateOpen(false);
-      setTitle('');
-      setSubject('');
+        setDialog(null);
         navigate(`/exam-marker/${created.id}/setup`);
+        return;
+      }
+
+      if (!dialog.template) return;
+
+      if (dialog.mode === 'duplicate') {
+        const created = await examRepository.duplicateTemplate(dialog.template.id, title);
+        setTemplates((prev) => [created, ...prev]);
+        setDialog(null);
+        navigate(`/exam-marker/${created.id}/setup`);
+        return;
+      }
+
+      const updated = await examRepository.updateTemplateMeta(dialog.template.id, {
+        title,
+        subject: subject.trim() || null,
+      });
+      setTemplates((prev) => prev.map((t) => (t.id === updated.id ? updated : t)));
+      setDialog(null);
     } catch (e) {
       const msg = e instanceof Error ? e.message : String(e);
-      logger.error('cc-exam-marker', 'Create template failed', { message: msg });
+      logger.error('cc-exam-marker', 'Template action failed', { message: msg, mode: dialog.mode });
       setError(msg);
     } finally {
       setSaving(false);
     }
   };
 
-  const handleArchive = async (id: string, ev: React.MouseEvent) => {
+  const handleArchive = async (template: ExamTemplate, ev: React.MouseEvent) => {
     ev.stopPropagation();
+    const parsed = splitTemplateTitle(template.title);
+    if (!window.confirm(`Archive ${parsed.name} ${parsed.version}? This hides it from the dashboard but keeps the work recoverable.`)) {
+      return;
+    }
     try {
-      await examRepository.archiveTemplate(id);
-      setTemplates((prev) => prev.filter((t) => t.id !== id));
+      await examRepository.archiveTemplate(template.id);
+      setTemplates((prev) => prev.filter((t) => t.id !== template.id));
     } catch (e) {
       const msg = e instanceof Error ? e.message : String(e);
       logger.error('cc-exam-marker', 'Archive failed', { message: msg });
@@ -100,6 +214,12 @@ const ExamDashboardPage: React.FC = () => {
     }
   };
 
+  const dialogTitle = dialog?.mode === 'edit'
+    ? 'Rename template / edit version'
+    : dialog?.mode === 'duplicate'
+      ? 'Duplicate as new version'
+      : 'New exam template';
+
   return (
     <Container maxWidth="lg" sx={{ py: 6 }}>
       <Stack spacing={4}>
@@ -108,11 +228,11 @@ const ExamDashboardPage: React.FC = () => {
             <Typography variant="h3" component="h1" gutterBottom>
               Exam Marker
             </Typography>
-            <Typography variant="body1" color="text.secondary" sx={{ maxWidth: 560 }}>
-              Build a template for an exam paper, then run marking batches against your classes.
+            <Typography variant="body1" color="text.secondary" sx={{ maxWidth: 620 }}>
+              Build multiple named templates for the same paper, version them as your setup changes, and archive drafts you no longer need.
             </Typography>
           </Box>
-          <Button variant="contained" startIcon={<AddIcon />} onClick={() => setCreateOpen(true)}>
+          <Button variant="contained" startIcon={<AddIcon />} onClick={openCreate}>
             New template
           </Button>
         </Box>
@@ -132,29 +252,61 @@ const ExamDashboardPage: React.FC = () => {
             <AssignmentIcon sx={{ fontSize: 48, color: 'text.disabled', mb: 1 }} />
             <Typography variant="h6" gutterBottom>No exam templates yet</Typography>
             <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
-              Create your first template to start mapping an exam paper.
+              Create your first named template to start mapping an exam paper.
             </Typography>
-            <Button variant="outlined" startIcon={<AddIcon />} onClick={() => setCreateOpen(true)}>
+            <Button variant="outlined" startIcon={<AddIcon />} onClick={openCreate}>
               New template
             </Button>
           </Paper>
         ) : (
+          <Stack spacing={3}>
+            {groupedTemplates.map((group) => (
+              <Box key={group.key}>
+                <Stack direction="row" spacing={1} alignItems="center" sx={{ mb: 1 }}>
+                  <Typography variant="h6">{group.label}</Typography>
+                  <Chip size="small" label={`${group.templates.length} template${group.templates.length === 1 ? '' : 's'}`} variant="outlined" />
+                </Stack>
                 <Grid container spacing={3}>
-            {templates.map((t) => (
+                  {group.templates.map((t) => {
+                    const parsed = splitTemplateTitle(t.title);
+                    return (
                       <Grid item xs={12} sm={6} md={4} key={t.id}>
                         <Paper
                           elevation={2}
-                  sx={{ p: 3, height: '100%', cursor: 'pointer', display: 'flex', flexDirection: 'column', gap: 1,
-                        transition: 'box-shadow 120ms', '&:hover': { boxShadow: 6 } }}
+                          sx={{
+                            p: 3,
+                            height: '100%',
+                            cursor: 'pointer',
+                            display: 'flex',
+                            flexDirection: 'column',
+                            gap: 1,
+                            transition: 'box-shadow 120ms',
+                            '&:hover': { boxShadow: 6 },
+                          }}
                           onClick={() => navigate(`/exam-marker/${t.id}/setup`)}
                         >
-                  <Box sx={{ display: 'flex', alignItems: 'flex-start', justifyContent: 'space-between' }}>
-                    <Typography variant="h6" sx={{ pr: 1 }}>{t.title}</Typography>
+                          <Box sx={{ display: 'flex', alignItems: 'flex-start', justifyContent: 'space-between', gap: 1 }}>
+                            <Box sx={{ minWidth: 0 }}>
+                              <Typography variant="h6" sx={{ pr: 1 }}>{parsed.name}</Typography>
+                              <Chip size="small" label={parsed.version} color="info" variant="outlined" sx={{ mt: 0.5 }} />
+                            </Box>
+                            <Stack direction="row" spacing={0.5}>
+                              <Tooltip title="Rename / edit version">
+                                <IconButton size="small" onClick={(e) => openEdit(t, e)} aria-label="rename template">
+                                  <EditIcon fontSize="small" />
+                                </IconButton>
+                              </Tooltip>
+                              <Tooltip title="Duplicate as new version">
+                                <IconButton size="small" onClick={(e) => openDuplicate(t, e)} aria-label="duplicate template">
+                                  <ContentCopyIcon fontSize="small" />
+                                </IconButton>
+                              </Tooltip>
                               <Tooltip title="Archive">
-                      <IconButton size="small" onClick={(e) => handleArchive(t.id, e)} aria-label="archive template">
+                                <IconButton size="small" onClick={(e) => handleArchive(t, e)} aria-label="archive template">
                                   <ArchiveIcon fontSize="small" />
                                 </IconButton>
                               </Tooltip>
+                            </Stack>
                           </Box>
                           {t.subject && (
                             <Typography variant="body2" color="text.secondary">{t.subject}</Typography>
@@ -165,40 +317,53 @@ const ExamDashboardPage: React.FC = () => {
                           <Box sx={{ mt: 'auto', pt: 1, display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
                             <Chip size="small" label={t.status} color={STATUS_COLOR[t.status] ?? 'default'} variant="outlined" />
                             <Typography variant="caption" color="text.secondary">
-                      {new Date(t.updated_at).toLocaleDateString()}
+                              Updated {new Date(t.updated_at).toLocaleDateString()}
                             </Typography>
                           </Box>
                         </Paper>
                       </Grid>
-            ))}
+                    );
+                  })}
                 </Grid>
+              </Box>
+            ))}
+          </Stack>
         )}
       </Stack>
 
-      <Dialog open={createOpen} onClose={() => (saving ? null : setCreateOpen(false))} fullWidth maxWidth="sm">
-        <DialogTitle>New exam template</DialogTitle>
+      <Dialog open={Boolean(dialog)} onClose={closeDialog} fullWidth maxWidth="sm">
+        <DialogTitle>{dialogTitle}</DialogTitle>
         <DialogContent>
           <Stack spacing={2} sx={{ mt: 1 }}>
             <TextField
-              label="Title"
-              value={title}
-              onChange={(e) => setTitle(e.target.value)}
+              label="Template name"
+              value={templateName}
+              onChange={(e) => setTemplateName(e.target.value)}
               fullWidth
               autoFocus
               required
+              helperText="User-facing name. Several templates can share the same paper."
             />
             <TextField
-              label="Subject"
+              label="Version"
+              value={version}
+              onChange={(e) => setVersion(e.target.value)}
+              fullWidth
+              helperText="Stored in the template title until the API grows a dedicated version column."
+            />
+            <TextField
+              label="Paper / subject label"
               value={subject}
               onChange={(e) => setSubject(e.target.value)}
               fullWidth
+              disabled={dialog?.mode === 'duplicate'}
             />
           </Stack>
         </DialogContent>
         <DialogActions>
-          <Button onClick={() => setCreateOpen(false)} disabled={saving}>Cancel</Button>
-          <Button variant="contained" onClick={handleCreate} disabled={saving || !title.trim()}>
-            {saving ? 'Creating…' : 'Create'}
+          <Button onClick={closeDialog} disabled={saving}>Cancel</Button>
+          <Button variant="contained" onClick={handleSaveDialog} disabled={saving || !templateName.trim()}>
+            {saving ? 'Saving…' : dialog?.mode === 'duplicate' ? 'Create version' : 'Save'}
           </Button>
         </DialogActions>
       </Dialog>

src/pages/exam/index.ts

@@ -1 +1,2 @@
 export { default as ExamDashboardPage } from './ExamDashboardPage';
+export { default as ExamTemplateSetupPage } from './setup/ExamTemplateSetupPage';

src/pages/exam/setup/ExamTemplateSetupPage.tsx

@@ -0,0 +1,286 @@
+
+import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useNavigate, useParams } from 'react-router-dom'
+import { Alert, Box, Button, Chip, CircularProgress, Divider, Paper, Snackbar, Stack, Tooltip, Typography, useTheme } from '@mui/material'
+import ArrowBackIcon from '@mui/icons-material/ArrowBack'
+import SaveIcon from '@mui/icons-material/Save'
+import MouseIcon from '@mui/icons-material/Mouse'
+import '@tldraw/tldraw/tldraw.css'
+import { Editor, Tldraw, createShapeId, TLShape } from '@tldraw/tldraw'
+import axios from 'axios'
+
+import { ErrorBoundary } from '../../../components/ErrorBoundary'
+import { logger } from '../../../debugConfig'
+import { examRepository } from '../../../services/exam/examRepository'
+import type { ExamTemplateDetail } from '../../../types/exam.types'
+import { CanvasPageGeometry, ExamCanvasShapeModel, PAGE_HEIGHT, PAGE_WIDTH, isUuid, newDomainId, serializeCanvasShapes, shapesFromTemplate } from '../../../utils/exam-canvas/model'
+import { PDF_PAGE_SHAPE_TYPE, examCanvasShapeUtils, examCanvasTools, ExamCanvasTLShape, SHAPE_TYPES, isPdfPageShape, shapeTypeToKind } from './examCanvasShapes'
+import { loadPdfPageImages, PdfPageImage } from './pdfLoader'
+
+const TOOLS = [
+  { id: 'select', label: 'Select', tip: 'Move, resize, or delete shapes.', color: 'inherit' as const },
+  { id: SHAPE_TYPES.boundary, label: 'Boundary', tip: 'Draw one horizontal line. A main question is saved from each top+bottom pair.', color: 'error' as const },
+  { id: SHAPE_TYPES.part, label: 'Part', tip: 'Draw the markable sub-question box inside a boundary pair.', color: 'warning' as const },
+  { id: SHAPE_TYPES.response, label: 'Response', tip: 'Draw around where the student writes; saved with response_form=lines.', color: 'primary' as const },
+  { id: SHAPE_TYPES.context, label: 'Context', tip: 'Draw around stimulus/context material; saved with context_type=generic.', color: 'secondary' as const },
+  { id: SHAPE_TYPES.question_number, label: 'Q Number', tip: 'Box the printed question number.', color: 'success' as const },
+  { id: SHAPE_TYPES.mark_area, label: 'Mark Area', tip: 'Box printed marks such as [2].', color: 'success' as const },
+  { id: SHAPE_TYPES.reference, label: 'Reference', tip: 'Box student resources/reference material.', color: 'info' as const },
+  { id: SHAPE_TYPES.furniture, label: 'Furniture', tip: 'Mark margins/page numbers/ignored decoration.', color: 'inherit' as const },
+]
+
+const PAGE_START_X = 260
+const PDF_PAGE_IDS_PREFIX = 'pdf-page-'
+
+function pageGeometryFromImages(pages: PdfPageImage[]): CanvasPageGeometry[] {
+  let y = 0
+  return pages.map((page) => {
+    const geometry = { pageNumber: page.pageNumber, x: PAGE_START_X, y, w: page.width, h: page.height }
+    y += page.height
+    return geometry
+  })
+}
+
+function apiMessage(err: unknown): { message: string; conflict: boolean } {
+  if (axios.isAxiosError(err)) {
+    const detail = (err.response?.data as { detail?: string } | undefined)?.detail
+    if (err.response?.status === 409) return { conflict: true, message: detail ?? 'Template has recorded marks; structural full-replace is blocked.' }
+    return { conflict: false, message: detail ?? err.message }
+  }
+  return { conflict: false, message: err instanceof Error ? err.message : String(err) }
+}
+
+function stripShapePrefix(id: string) {
+  return id.startsWith('shape:') ? id.slice('shape:'.length) : id
+}
+
+function domainIdForShape(shape: ExamCanvasTLShape): string {
+  const fromProps = shape.props.domainId
+  if (isUuid(fromProps)) return fromProps
+  const fromShapeId = stripShapePrefix(shape.id)
+  return isUuid(fromShapeId) ? fromShapeId : newDomainId()
+}
+
+function ensureDomainIds(editor: Editor) {
+  const updates = editor.getCurrentPageShapes()
+    .filter((shape): shape is ExamCanvasTLShape => !!shapeTypeToKind(shape.type))
+    .filter((shape) => !isUuid(shape.props.domainId))
+    .map((shape) => ({ id: shape.id, type: shape.type, props: { domainId: domainIdForShape(shape) } }))
+  if (updates.length) editor.updateShapes(updates)
+}
+
+function modelFromTLShape(shape: TLShape): ExamCanvasShapeModel | null {
+  const kind = shapeTypeToKind(shape.type)
+  if (!kind) return null
+  const s = shape as ExamCanvasTLShape
+  return {
+    id: domainIdForShape(s),
+    kind,
+    x: Number(s.x ?? 0),
+    y: Number(s.y ?? 0),
+    w: Number(s.props.w ?? 1),
+    h: Number(s.props.h ?? 1),
+    label: s.props.label,
+    maxMarks: s.props.maxMarks,
+    responseForm: s.props.responseForm as ExamCanvasShapeModel['responseForm'],
+    contextType: s.props.contextType,
+    questionId: s.props.questionId ?? null,
+  }
+}
+
+function loadShapes(editor: Editor, models: ExamCanvasShapeModel[]) {
+  const existing = editor.getCurrentPageShapes().filter((s) => shapeTypeToKind(s.type)).map((s) => s.id)
+  if (existing.length) editor.deleteShapes(existing)
+  if (!models.length) return
+  editor.createShapes(models.map((m) => ({
+    id: createShapeId(m.id),
+    type: SHAPE_TYPES[m.kind],
+    x: m.x,
+    y: m.y,
+    props: { w: m.w, h: m.h, label: m.label ?? m.kind, kind: m.kind, maxMarks: m.maxMarks, responseForm: m.responseForm, contextType: m.contextType, questionId: m.questionId, domainId: m.id },
+  })))
+}
+
+function syncPdfPages(editor: Editor, pages: PdfPageImage[]) {
+  const existing = editor.getCurrentPageShapes().filter((s) => isPdfPageShape(s.type)).map((s) => s.id)
+  if (existing.length) editor.deleteShapes(existing)
+  if (!pages.length) return
+  const geometries = pageGeometryFromImages(pages)
+  editor.createShapes(geometries.map((geometry) => {
+    const page = pages[geometry.pageNumber - 1]
+    return {
+      id: createShapeId(PDF_PAGE_IDS_PREFIX + geometry.pageNumber),
+      type: PDF_PAGE_SHAPE_TYPE,
+      x: geometry.x,
+      y: geometry.y,
+      isLocked: true,
+      props: { w: geometry.w, h: geometry.h, src: page.src, pageNumber: geometry.pageNumber },
+    } as any
+  }))
+  const ids = geometries.map((geometry) => createShapeId(PDF_PAGE_IDS_PREFIX + geometry.pageNumber))
+  try { editor.sendToBack(ids as any) } catch { /* tldraw 3 keeps creation order behind later region shapes */ }
+}
+
+function seedGuide(editor: Editor) {
+  const current = editor.getCurrentPageShapes().filter((s) => shapeTypeToKind(s.type))
+  if (current.length) return
+  editor.createShapes([
+    { id: createShapeId(newDomainId()), type: SHAPE_TYPES.boundary, x: 48, y: 120, props: { w: PAGE_WIDTH - 96, h: 8, kind: 'boundary', label: 'Q1 start', domainId: newDomainId() } },
+    { id: createShapeId(newDomainId()), type: SHAPE_TYPES.boundary, x: 48, y: 520, props: { w: PAGE_WIDTH - 96, h: 8, kind: 'boundary', label: 'Q1 end', domainId: newDomainId() } },
+    { id: createShapeId(newDomainId()), type: SHAPE_TYPES.part, x: 92, y: 180, props: { w: 520, h: 150, kind: 'part', label: 'Q1(a)', maxMarks: 3, domainId: newDomainId() } },
+    { id: createShapeId(newDomainId()), type: SHAPE_TYPES.response, x: 116, y: 355, props: { w: 470, h: 120, kind: 'response', label: 'Response', responseForm: 'lines', domainId: newDomainId() } },
+  ])
+}
+
+const ExamTemplateSetupInner: React.FC = () => {
+  const { templateId } = useParams<{ templateId: string }>()
+  const navigate = useNavigate()
+  const theme = useTheme()
+  const editorRef = useRef<Editor | null>(null)
+  const pageGeometriesRef = useRef<CanvasPageGeometry[]>([])
+  const [template, setTemplate] = useState<ExamTemplateDetail | null>(null)
+  const [loading, setLoading] = useState(true)
+  const [saving, setSaving] = useState(false)
+  const [dirty, setDirty] = useState(false)
+  const [error, setError] = useState<string | null>(null)
+  const [conflict, setConflict] = useState<string | null>(null)
+  const [activeTool, setActiveTool] = useState('select')
+  const [pdfStatus, setPdfStatus] = useState<'loading' | 'ready' | 'missing' | 'error'>('loading')
+  const [pdfError, setPdfError] = useState<string | null>(null)
+
+  const load = useCallback(async () => {
+    if (!templateId) return
+    setLoading(true); setError(null); setConflict(null)
+    try {
+      const detail = await examRepository.getTemplate(templateId)
+      setTemplate(detail)
+      let pages: PdfPageImage[] = []
+      setPdfStatus('loading')
+      setPdfError(null)
+      try {
+        const bytes = await examRepository.getTemplateSourcePdf(templateId)
+        pages = await loadPdfPageImages(bytes)
+        setPdfStatus(pages.length ? 'ready' : 'missing')
+      } catch (pdfErr) {
+        const pdfMsg = apiMessage(pdfErr).message
+        setPdfStatus(pdfMsg.toLowerCase().includes('404') ? 'missing' : 'error')
+        setPdfError(pdfMsg)
+        logger.warn('cc-exam-marker', 'Template source PDF load failed', { templateId, message: pdfMsg })
+      }
+      const geometries = pageGeometryFromImages(pages)
+      pageGeometriesRef.current = geometries
+      const editor = editorRef.current
+      if (editor) {
+        syncPdfPages(editor, pages)
+        loadShapes(editor, shapesFromTemplate(detail, geometries))
+      }
+      setDirty(false)
+    } catch (e) {
+      const msg = apiMessage(e).message
+      logger.warn('cc-exam-marker', 'Template setup load failed', { templateId, message: msg })
+      setError(msg)
+    } finally {
+      setLoading(false)
+    }
+  }, [templateId])
+
+  useEffect(() => { void load() }, [load])
+
+  const save = useCallback(async () => {
+    const editor = editorRef.current
+    if (!editor || !templateId || !template) return
+    setSaving(true); setError(null); setConflict(null)
+    try {
+      ensureDomainIds(editor)
+      const shapes = editor.getCurrentPageShapes().map(modelFromTLShape).filter(Boolean) as ExamCanvasShapeModel[]
+      const payload = serializeCanvasShapes(template, shapes, pageGeometriesRef.current)
+      const saved = await examRepository.replaceTemplate(templateId, payload)
+      setTemplate(saved)
+      loadShapes(editor, shapesFromTemplate(saved, pageGeometriesRef.current))
+      setDirty(false)
+    } catch (e) {
+      const msg = apiMessage(e)
+      if (msg.conflict) setConflict(msg.message); else setError(msg.message)
+      logger.warn('cc-exam-marker', 'Template setup save failed', { templateId, message: msg.message })
+    } finally {
+      setSaving(false)
+    }
+  }, [template, templateId])
+
+  const toolButtons = useMemo(() => TOOLS.map((tool) => (
+    <Tooltip title={tool.tip} key={tool.id} placement="right">
+      <Button
+        size="small"
+        variant={activeTool === tool.id ? 'contained' : 'outlined'}
+        color={tool.color}
+        startIcon={tool.id === 'select' ? <MouseIcon fontSize="small" /> : undefined}
+        onClick={() => {
+          const editor = editorRef.current
+          if (!editor) return
+          editor.setCurrentTool(tool.id === 'select' ? 'select' : tool.id)
+          setActiveTool(tool.id)
+        }}
+        sx={{ justifyContent: 'flex-start', minWidth: 126 }}
+      >
+        {tool.label}
+      </Button>
+    </Tooltip>
+  )), [activeTool])
+
+  return (
+    <Box sx={{ position: 'fixed', inset: 0, zIndex: (t) => t.zIndex.drawer + 20, bgcolor: 'background.default' }}>
+      <Box sx={{ position: 'absolute', inset: 0, '& .tlui-layout': { display: 'none' } }} data-testid="exam-template-setup-canvas">
+        <Tldraw
+          shapeUtils={examCanvasShapeUtils as any}
+          tools={examCanvasTools as any}
+          hideUi
+          inferDarkMode={theme.palette.mode === 'dark'}
+          autoFocus
+          onMount={(editor) => {
+            editorRef.current = editor
+            editor.user.updateUserPreferences({ colorScheme: theme.palette.mode === 'dark' ? 'dark' : 'light' })
+            editor.store.listen(() => setDirty(true), { scope: 'document' })
+            if (template) loadShapes(editor, shapesFromTemplate(template, pageGeometriesRef.current)); else seedGuide(editor)
+          }}
+        />
+      </Box>
+
+      <Paper elevation={8} sx={{ position: 'absolute', top: 12, left: 12, right: 12, px: 2, py: 1.25, display: 'flex', alignItems: 'center', gap: 1.5, borderRadius: 3, bgcolor: 'background.paper' }}>
+        <Button startIcon={<ArrowBackIcon />} onClick={() => navigate('/exam-marker')} size="small">Back</Button>
+        <Divider orientation="vertical" flexItem />
+        <Box sx={{ minWidth: 0, flex: 1 }}>
+          <Typography variant="subtitle1" noWrap>{template?.title ?? 'Template setup'}</Typography>
+          <Typography variant="caption" color="text.secondary">Exam Marker › Setup · draw boundaries, part boxes, and regions; Save persists a full replace.</Typography>
+        </Box>
+        <Chip size="small" color={dirty ? 'warning' : 'success'} label={dirty ? 'Unsaved' : 'Saved'} />
+        <Button variant="contained" startIcon={saving ? <CircularProgress size={16} color="inherit" /> : <SaveIcon />} onClick={save} disabled={saving || loading || !template}>Save</Button>
+      </Paper>
+
+      <Paper elevation={8} sx={{ position: 'absolute', top: 92, left: 12, p: 1.25, borderRadius: 3, bgcolor: 'background.paper' }}>
+        <Stack spacing={1}>{toolButtons}</Stack>
+      </Paper>
+
+      <Paper elevation={4} sx={{ position: 'absolute', right: 16, bottom: 16, maxWidth: 420, p: 2, borderRadius: 3, bgcolor: 'background.paper' }}>
+        <Typography variant="subtitle2" gutterBottom>Setup guide</Typography>
+        <Typography variant="body2" color="text.secondary">
+          1) Draw top and bottom Boundary lines for each main question. 2) Draw Part boxes inside the pair. 3) Draw Response/Context/metadata regions inside a Part. Save derives parent links by spatial containment and reloads from the API.
+        </Typography>
+        <Typography variant="caption" color={pdfStatus === 'ready' ? 'success.main' : pdfStatus === 'error' ? 'error.main' : 'text.secondary'} sx={{ display: 'block', mt: 1 }}>
+          PDF backdrop: {pdfStatus === 'ready' ? 'loaded and locked behind regions' : pdfStatus === 'loading' ? 'loading…' : pdfStatus === 'missing' ? 'no source PDF for this template' : pdfError ?? 'failed to load'}
+        </Typography>
+      </Paper>
+
+      {loading && <Box sx={{ position: 'absolute', inset: 0, display: 'grid', placeItems: 'center', bgcolor: 'rgba(15,23,42,.18)' }}><CircularProgress /></Box>}
+      {conflict && <Alert severity="warning" sx={{ position: 'absolute', top: 86, right: 16, maxWidth: 560 }} onClose={() => setConflict(null)}>{conflict}</Alert>}
+      <Snackbar open={!!error} autoHideDuration={8000} onClose={() => setError(null)}><Alert severity="error" onClose={() => setError(null)}>{error}</Alert></Snackbar>
+    </Box>
+  )
+}
+
+const ExamTemplateSetupPage: React.FC = () => (
+  <ErrorBoundary fallback={<Box sx={{ p: 4 }}><Alert severity="error">Template setup canvas crashed. Reload the page and try again.</Alert></Box>}>
+    <ExamTemplateSetupInner />
+  </ErrorBoundary>
+)
+
+export default ExamTemplateSetupPage

src/pages/exam/setup/examCanvasShapes.tsx

@@ -0,0 +1,117 @@
+
+import React from 'react'
+import { BaseBoxShapeTool, BaseBoxShapeUtil, HTMLContainer, T, TLBaseBoxShape, toDomPrecision } from '@tldraw/tldraw'
+import type { ExamCanvasRegionKind, ExamCanvasShapeKind } from '../../../utils/exam-canvas/model'
+
+export const PDF_PAGE_SHAPE_TYPE = 'exam-pdf-page'
+
+export const SHAPE_TYPES = {
+  boundary: 'exam-boundary',
+  part: 'exam-part',
+  response: 'exam-region-response',
+  context: 'exam-region-context',
+  question_number: 'exam-region-question-number',
+  mark_area: 'exam-region-mark-area',
+  reference: 'exam-region-reference',
+  furniture: 'exam-region-furniture',
+} as const
+
+export type ExamPdfPageTLShape = TLBaseBoxShape & {
+  type: typeof PDF_PAGE_SHAPE_TYPE
+  props: { w: number; h: number; src: string; pageNumber: number }
+}
+
+export type ExamCanvasTLShape = TLBaseBoxShape & {
+  type: typeof SHAPE_TYPES[keyof typeof SHAPE_TYPES]
+  props: {
+    w: number
+    h: number
+    label: string
+    kind: ExamCanvasShapeKind
+    maxMarks?: number
+    responseForm?: string
+    contextType?: string
+    questionId?: string | null
+    domainId?: string
+  }
+}
+
+const palette: Record<ExamCanvasShapeKind, { stroke: string; fill: string; dash?: string; label: string }> = {
+  boundary: { stroke: '#ef4444', fill: 'rgba(239,68,68,0.06)', dash: '8 6', label: 'Boundary' },
+  part: { stroke: '#f59e0b', fill: 'rgba(245,158,11,0.16)', label: 'Part' },
+  response: { stroke: '#2563eb', fill: 'rgba(37,99,235,0.16)', label: 'Response' },
+  context: { stroke: '#7c3aed', fill: 'rgba(124,58,237,0.14)', dash: '6 5', label: 'Context' },
+  question_number: { stroke: '#0f766e', fill: 'rgba(15,118,110,0.14)', label: 'Question #' },
+  mark_area: { stroke: '#16a34a', fill: 'rgba(22,163,74,0.14)', label: 'Marks' },
+  reference: { stroke: '#0891b2', fill: 'rgba(8,145,178,0.14)', label: 'Reference' },
+  furniture: { stroke: '#64748b', fill: 'rgba(100,116,139,0.12)', dash: '3 5', label: 'Furniture' },
+}
+
+function renderShape(shape: ExamCanvasTLShape) {
+  const kind = shape.props.kind
+  const p = palette[kind] ?? palette.response
+  const isBoundary = kind === 'boundary'
+  return (
+    <HTMLContainer id={shape.id} style={{ width: toDomPrecision(shape.props.w), height: toDomPrecision(shape.props.h), pointerEvents: 'all' }}>
+      <div style={{
+        width: '100%', height: '100%', boxSizing: 'border-box', border: `${isBoundary ? 2 : 1.5}px solid ${p.stroke}`,
+        borderStyle: p.dash ? 'dashed' : 'solid', borderRadius: isBoundary ? 999 : 10,
+        background: isBoundary ? 'transparent' : p.fill, color: p.stroke, fontFamily: 'Inter, system-ui, sans-serif',
+        display: 'flex', alignItems: isBoundary ? 'center' : 'flex-start', justifyContent: isBoundary ? 'center' : 'space-between',
+        padding: isBoundary ? '0 8px' : 8, boxShadow: isBoundary ? 'none' : '0 10px 22px rgba(15,23,42,0.08)', overflow: 'hidden'
+      }}>
+        <span style={{ fontSize: 12, fontWeight: 800, textTransform: 'uppercase', letterSpacing: 0.6, background: 'rgba(255,255,255,0.84)', borderRadius: 999, padding: '2px 7px' }}>
+          {shape.props.label || p.label}
+        </span>
+        {!isBoundary && shape.props.questionId && <span style={{ fontSize: 11, fontWeight: 700, opacity: .75 }}>Attached</span>}
+      </div>
+    </HTMLContainer>
+  )
+}
+
+function defaultProps(kind: ExamCanvasShapeKind, w: number, h: number) {
+  const p = palette[kind]
+  return { w, h, label: p.label, kind, responseForm: kind === 'response' ? 'lines' : undefined, contextType: kind === 'context' ? 'generic' : undefined }
+}
+
+const sharedProps = { w: T.number, h: T.number, label: T.string, kind: T.string, maxMarks: T.optional(T.number), responseForm: T.optional(T.string), contextType: T.optional(T.string), questionId: T.optional(T.string), domainId: T.optional(T.string) }
+const ind = (s: ExamCanvasTLShape | ExamPdfPageTLShape) => <rect width={toDomPrecision(s.props.w)} height={toDomPrecision(s.props.h)} />
+
+class PdfPageUtil extends BaseBoxShapeUtil<ExamPdfPageTLShape> {
+  static override type = PDF_PAGE_SHAPE_TYPE
+  static override props = { w: T.number, h: T.number, src: T.string, pageNumber: T.number }
+  override getDefaultProps() { return { w: 780, h: 1100, src: '', pageNumber: 1 } }
+  override canEdit() { return false }
+  override component(shape: ExamPdfPageTLShape) {
+    return (
+      <HTMLContainer id={shape.id} style={{ width: toDomPrecision(shape.props.w), height: toDomPrecision(shape.props.h), pointerEvents: 'none' }}>
+        <img src={shape.props.src} alt={'PDF page ' + shape.props.pageNumber} draggable={false} style={{ width: '100%', height: '100%', display: 'block', userSelect: 'none', pointerEvents: 'none', boxShadow: '0 2px 16px rgba(15,23,42,0.18)', background: '#fff' }} />
+      </HTMLContainer>
+    )
+  }
+  override indicator(shape: ExamPdfPageTLShape) { return ind(shape) }
+}
+class BoundaryUtil extends BaseBoxShapeUtil<ExamCanvasTLShape> { static override type = SHAPE_TYPES.boundary; static override props = sharedProps; override getDefaultProps(){ return defaultProps('boundary', 680, 8) }; override component(shape: ExamCanvasTLShape){ return renderShape(shape) }; override indicator(shape: ExamCanvasTLShape){ return ind(shape) } }
+class PartUtil extends BaseBoxShapeUtil<ExamCanvasTLShape> { static override type = SHAPE_TYPES.part; static override props = sharedProps; override getDefaultProps(){ return defaultProps('part', 420, 170) }; override component(shape: ExamCanvasTLShape){ return renderShape(shape) }; override indicator(shape: ExamCanvasTLShape){ return ind(shape) } }
+function regionUtil(type: string, kind: ExamCanvasRegionKind, w = 360, h = 120) { return class extends BaseBoxShapeUtil<ExamCanvasTLShape> { static override type = type; static override props = sharedProps; override getDefaultProps(){ return defaultProps(kind, w, h) }; override component(shape: ExamCanvasTLShape){ return renderShape(shape) }; override indicator(shape: ExamCanvasTLShape){ return ind(shape) } } }
+
+class BoundaryTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.boundary; static override initial = 'pointing'; shapeType = SHAPE_TYPES.boundary }
+class PartTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.part; static override initial = 'pointing'; shapeType = SHAPE_TYPES.part }
+class ResponseTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.response; static override initial = 'pointing'; shapeType = SHAPE_TYPES.response }
+class ContextTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.context; static override initial = 'pointing'; shapeType = SHAPE_TYPES.context }
+class QuestionNumberTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.question_number; static override initial = 'pointing'; shapeType = SHAPE_TYPES.question_number }
+class MarkAreaTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.mark_area; static override initial = 'pointing'; shapeType = SHAPE_TYPES.mark_area }
+class ReferenceTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.reference; static override initial = 'pointing'; shapeType = SHAPE_TYPES.reference }
+class FurnitureTool extends BaseBoxShapeTool { static override id = SHAPE_TYPES.furniture; static override initial = 'pointing'; shapeType = SHAPE_TYPES.furniture }
+
+export const examCanvasShapeUtils = [PdfPageUtil, BoundaryUtil, PartUtil, regionUtil(SHAPE_TYPES.response, 'response'), regionUtil(SHAPE_TYPES.context, 'context'), regionUtil(SHAPE_TYPES.question_number, 'question_number', 170, 80), regionUtil(SHAPE_TYPES.mark_area, 'mark_area', 170, 80), regionUtil(SHAPE_TYPES.reference, 'reference'), regionUtil(SHAPE_TYPES.furniture, 'furniture')] as const
+export const examCanvasTools = [BoundaryTool, PartTool, ResponseTool, ContextTool, QuestionNumberTool, MarkAreaTool, ReferenceTool, FurnitureTool] as const
+
+export function isPdfPageShape(type: string): boolean {
+  return type === PDF_PAGE_SHAPE_TYPE
+}
+
+export function shapeTypeToKind(type: string): ExamCanvasShapeKind | null {
+  const entry = Object.entries(SHAPE_TYPES).find(([, v]) => v === type)
+  return (entry?.[0] as ExamCanvasShapeKind | undefined) ?? null
+}

src/pages/exam/setup/pdfLoader.ts

@@ -0,0 +1,39 @@
+import * as pdfjsLib from "pdfjs-dist"
+import pdfWorkerSrc from "pdfjs-dist/build/pdf.worker.mjs?url"
+
+import { PAGE_WIDTH } from "../../../utils/exam-canvas/model"
+
+pdfjsLib.GlobalWorkerOptions.workerSrc = pdfWorkerSrc
+
+export interface PdfPageImage {
+  pageNumber: number
+  src: string
+  width: number
+  height: number
+}
+
+export async function loadPdfPageImages(pdfBytes: ArrayBuffer, targetWidth = PAGE_WIDTH): Promise<PdfPageImage[]> {
+  const pdf = await pdfjsLib.getDocument({ data: new Uint8Array(pdfBytes) }).promise
+  const pages: PdfPageImage[] = []
+
+  for (let pageNumber = 1; pageNumber <= pdf.numPages; pageNumber += 1) {
+    const page = await pdf.getPage(pageNumber)
+    const baseViewport = page.getViewport({ scale: 1 })
+    const scale = targetWidth / baseViewport.width
+    const viewport = page.getViewport({ scale })
+    const canvas = document.createElement("canvas")
+    canvas.width = Math.ceil(viewport.width)
+    canvas.height = Math.ceil(viewport.height)
+    const context = canvas.getContext("2d")
+    if (!context) throw new Error("Unable to create PDF render canvas")
+    await page.render({ canvasContext: context, viewport }).promise
+    pages.push({
+      pageNumber,
+      src: canvas.toDataURL("image/png"),
+      width: canvas.width,
+      height: canvas.height,
+    })
+  }
+
+  return pages
+}

src/services/exam/examRepository.ts

@@ -8,11 +8,17 @@
 import axios from 'axios';
 
 import { API_BASE } from '../../config/apiConfig';
+import { logger } from '../../debugConfig';
 import { supabase } from '../../supabaseClient';
 import type {
   CreateTemplatePayload,
+  ExamBoundary,
+  ExamQuestion,
+  ExamResponseArea,
   ExamTemplate,
   ExamTemplateDetail,
+  TemplateReplacePayload,
+  UpdateTemplateMetaPayload,
 } from '../../types/exam.types';
 
 const EXAM_BASE = `${API_BASE}/api/exam`;
@@ -25,6 +31,86 @@ async function authHeaders(): Promise<Record<string, string>> {
   return { Authorization: `Bearer ${session.access_token}` };
 }
 
+function newUuid(): string {
+  if (typeof crypto !== 'undefined' && 'randomUUID' in crypto) {
+    return crypto.randomUUID();
+  }
+  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
+    const r = Math.floor(Math.random() * 16);
+    const v = c === 'x' ? r : (r % 4) + 8;
+    return v.toString(16);
+  });
+}
+
+function questionPayload(q: ExamQuestion, idMap?: Map<string, string>) {
+  return {
+    id: idMap?.get(q.id) ?? q.id,
+    parent_id: q.parent_id ? (idMap?.get(q.parent_id) ?? q.parent_id) : null,
+    label: q.label,
+    order: q.order,
+    max_marks: q.max_marks,
+    answer_type: q.answer_type,
+    mcq_options: q.mcq_options,
+    mark_scheme: q.mark_scheme ?? {},
+    is_container: q.is_container,
+    spec_ref: q.spec_ref,
+    bounds: q.bounds ?? null,
+    page: q.page ?? null,
+  };
+}
+
+function responseAreaPayload(r: ExamResponseArea, idMap?: Map<string, string>, duplicate = false) {
+  return {
+    id: duplicate ? newUuid() : r.id,
+    question_id: idMap?.get(r.question_id) ?? r.question_id,
+    page: r.page,
+    bounds: r.bounds,
+    kind: r.kind,
+    response_form: r.response_form,
+    context_type: r.context_type ?? null,
+    source: r.source,
+    confirmed: r.confirmed,
+    confidence: r.confidence,
+  };
+}
+
+function boundaryPayload(b: ExamBoundary, idMap?: Map<string, string>, duplicate = false) {
+  return {
+    id: duplicate ? newUuid() : b.id,
+    question_id: b.question_id ? (idMap?.get(b.question_id) ?? b.question_id) : null,
+    label: b.label,
+    page_index: b.page_index,
+    y: b.y,
+    bounds: b.bounds,
+    source: b.source,
+    confirmed: b.confirmed,
+  };
+}
+
+async function replaceTemplate(
+  templateId: string,
+  detail: ExamTemplateDetail,
+  meta?: UpdateTemplateMetaPayload,
+  duplicateIds = false,
+): Promise<ExamTemplateDetail> {
+  const headers = await authHeaders();
+  const idMap = new Map<string, string>();
+  if (duplicateIds) {
+    detail.questions.forEach((q) => idMap.set(q.id, newUuid()));
+  }
+  const res = await axios.put<ExamTemplateDetail>(
+    `${EXAM_BASE}/templates/${templateId}`,
+    {
+      meta,
+      questions: detail.questions.map((q) => questionPayload(q, idMap)),
+      response_areas: detail.response_areas.map((r) => responseAreaPayload(r, idMap, duplicateIds)),
+      boundaries: detail.boundaries.map((b) => boundaryPayload(b, idMap, duplicateIds)),
+    },
+    { headers },
+  );
+  return res.data;
+}
+
 export const examRepository = {
   async listTemplates(includeArchived = false): Promise<ExamTemplate[]> {
     const headers = await authHeaders();
@@ -41,12 +127,59 @@ export const examRepository = {
     return res.data;
   },
 
+  async getTemplateSourcePdf(templateId: string): Promise<ArrayBuffer> {
+    const headers = await authHeaders();
+    const res = await axios.get<ArrayBuffer>(`${EXAM_BASE}/templates/${templateId}/source-pdf`, {
+      headers,
+      responseType: 'arraybuffer',
+    });
+    return res.data;
+  },
+
   async createTemplate(payload: CreateTemplatePayload): Promise<ExamTemplate> {
     const headers = await authHeaders();
     const res = await axios.post<ExamTemplate>(`${EXAM_BASE}/templates`, payload, { headers });
     return res.data;
   },
 
+  async updateTemplateMeta(templateId: string, meta: UpdateTemplateMetaPayload): Promise<ExamTemplate> {
+    const headers = await authHeaders();
+    const res = await axios.patch<ExamTemplate>(`${EXAM_BASE}/templates/${templateId}`, meta, { headers });
+    return res.data;
+  },
+
+  async duplicateTemplate(templateId: string, title: string): Promise<ExamTemplateDetail> {
+    const detail = await this.getTemplate(templateId);
+    const created = await this.createTemplate({
+      title,
+      subject: detail.subject ?? undefined,
+      exam_id: detail.exam_id ?? undefined,
+      exam_code: detail.exam_code ?? undefined,
+      source_file_id: detail.source_file_id ?? undefined,
+      page_count: detail.page_count ?? undefined,
+      institute_id: detail.institute_id,
+    });
+    try {
+      return await replaceTemplate(created.id, { ...detail, id: created.id }, { title, status: 'draft' }, true);
+    } catch (error) {
+      try {
+        await this.archiveTemplate(created.id);
+      } catch (archiveError) {
+        logger.error('cc-exam-marker', 'Failed to archive incomplete duplicate template', {
+          templateId: created.id,
+          message: archiveError instanceof Error ? archiveError.message : String(archiveError),
+        });
+      }
+      throw error;
+    }
+  },
+
+
+  async replaceTemplate(templateId: string, payload: TemplateReplacePayload): Promise<ExamTemplateDetail> {
+    const headers = await authHeaders();
+    const res = await axios.put<ExamTemplateDetail>(`${EXAM_BASE}/templates/${templateId}`, payload, { headers });
+    return res.data;
+  },
   async archiveTemplate(templateId: string): Promise<void> {
     const headers = await authHeaders();
     await axios.delete(`${EXAM_BASE}/templates/${templateId}`, { headers });

src/types/exam.types.ts

@@ -31,6 +31,13 @@ export interface CreateTemplatePayload {
   institute_id?: string;
 }
 
+export interface UpdateTemplateMetaPayload {
+  title?: string;
+  subject?: string | null;
+  page_count?: number | null;
+  status?: ExamTemplateStatus;
+}
+
 /** Canvas children (used from S4-9 onward; defined here so the seam is complete). */
 export interface ExamQuestion {
   id: string;
@@ -44,16 +51,27 @@ export interface ExamQuestion {
   mark_scheme: Record<string, unknown>;
   is_container: boolean;
   spec_ref: string | null;
+  bounds?: Record<string, number> | null;
+  page?: number | null;
 }
 
+export type ExamResponseAreaKind =
+  | 'response'
+  | 'context'
+  | 'question_number'
+  | 'mark_area'
+  | 'reference'
+  | 'furniture';
+
 export interface ExamResponseArea {
   id: string;
   question_id: string;
   template_id: string;
   page: number;
   bounds: Record<string, number>;
-  kind: 'response' | 'context';
+  kind: ExamResponseAreaKind;
   response_form: string | null;
+  context_type?: string | null;
   source: 'manual' | 'ai';
   confirmed: boolean;
   confidence: number | null;
@@ -76,3 +94,49 @@ export interface ExamTemplateDetail extends ExamTemplate {
   response_areas: ExamResponseArea[];
   boundaries: ExamBoundary[];
 }
+
+
+export interface TemplateReplacePayload {
+  meta?: {
+    title?: string;
+    subject?: string;
+    page_count?: number;
+    status?: ExamTemplateStatus;
+  };
+  questions: Array<{
+    id?: string;
+    parent_id?: string | null;
+    label: string;
+    order?: number;
+    max_marks?: number;
+    answer_type?: 'written' | 'mcq' | 'short' | 'diagram' | null;
+    mcq_options?: unknown | null;
+    mark_scheme?: Record<string, unknown>;
+    is_container?: boolean;
+    spec_ref?: string | null;
+    bounds?: Record<string, number> | null;
+    page?: number | null;
+  }>;
+  response_areas: Array<{
+    id?: string;
+    question_id: string;
+    page: number;
+    bounds: Record<string, number>;
+    kind: ExamResponseArea['kind'];
+    response_form?: string | null;
+    context_type?: string | null;
+    source?: 'manual' | 'ai';
+    confirmed?: boolean;
+    confidence?: number | null;
+  }>;
+  boundaries: Array<{
+    id?: string;
+    question_id?: string | null;
+    label?: string | null;
+    page_index: number;
+    y: number;
+    bounds?: Record<string, number> | null;
+    source?: 'manual' | 'ai';
+    confirmed?: boolean;
+  }>;
+}

src/utils/exam-canvas/model.test.ts

@@ -0,0 +1,65 @@
+import { describe, expect, it } from 'vitest'
+import type { ExamTemplateDetail } from '../../types/exam.types'
+import { isUuid, pageForY, serializeCanvasShapes, shapesFromTemplate } from './model'
+
+const template: ExamTemplateDetail = {
+  id: 'tpl-1', title: 'Physics', subject: 'Physics', exam_id: null, exam_code: null, source_file_id: null, page_count: 1,
+  institute_id: 'inst', teacher_id: 'teacher', status: 'draft', created_at: 'now', updated_at: 'now', questions: [], response_areas: [], boundaries: [],
+}
+
+describe('exam setup canvas serialization', () => {
+  it('pairs boundaries into a main question, attaches a Part, and attaches a response by containment', () => {
+    const payload = serializeCanvasShapes(template, [
+      { id: 'b-top', kind: 'boundary', x: 40, y: 100, w: 700, h: 8, label: 'Q1 start' },
+      { id: 'b-bottom', kind: 'boundary', x: 40, y: 700, w: 700, h: 8, label: 'Q1 end' },
+      { id: 'part-1', kind: 'part', x: 100, y: 180, w: 400, h: 220, label: 'Q1(a)', maxMarks: 3 },
+      { id: 'resp-1', kind: 'response', x: 130, y: 250, w: 300, h: 90, responseForm: 'lines' },
+    ])
+
+    const main = payload.questions.find((q) => q.is_container)
+    const part = payload.questions.find((q) => !q.is_container)
+    expect(main?.label).toBe('Q1')
+    expect(part?.parent_id).toBe(main?.id)
+    expect(part?.bounds).toEqual({ x: 100, y: 180, w: 400, h: 220 })
+    expect(payload.response_areas[0]).toMatchObject({ question_id: part?.id, kind: 'response', response_form: 'lines' })
+    expect(payload.boundaries).toHaveLength(2)
+    expect(payload.boundaries.every((b) => b.question_id === main?.id)).toBe(true)
+    expect(payload.questions.every((q) => isUuid(q.id))).toBe(true)
+    expect(payload.response_areas.every((r) => isUuid(r.id))).toBe(true)
+    expect(payload.boundaries.every((b) => isUuid(b.id))).toBe(true)
+  })
+
+  it('maps shapes to the visible PDF page geometry rather than a fixed page height', () => {
+    const pages = [
+      { pageNumber: 1, x: 260, y: 0, w: 780, h: 1000 },
+      { pageNumber: 2, x: 260, y: 1000, w: 780, h: 1200 },
+    ]
+    expect(pageForY(1050, pages)).toBe(2)
+    const payload = serializeCanvasShapes(template, [
+      { id: 'b-top', kind: 'boundary', x: 260, y: 1020, w: 700, h: 8, label: 'Q1 start' },
+      { id: 'b-bottom', kind: 'boundary', x: 260, y: 1700, w: 700, h: 8, label: 'Q1 end' },
+      { id: 'part-1', kind: 'part', x: 300, y: 1120, w: 300, h: 160, label: 'Q1(a)' },
+      { id: 'resp-1', kind: 'response', x: 320, y: 1160, w: 240, h: 80 },
+    ], pages)
+    expect(payload.questions.find((q) => !q.is_container)?.page).toBe(2)
+    expect(payload.boundaries.every((b) => b.page_index === 1)).toBe(true)
+    expect(payload.response_areas[0].page).toBe(2)
+  })
+
+  it('round-trips saved Part geometry and all S4-9 region kinds from API detail', () => {
+    const shapes = shapesFromTemplate({
+      ...template,
+      questions: [
+        { id: 'q1', template_id: 'tpl-1', parent_id: null, label: 'Q1', order: 0, max_marks: 0, answer_type: null, mcq_options: null, mark_scheme: {}, is_container: true, spec_ref: null },
+        { id: 'p1', template_id: 'tpl-1', parent_id: 'q1', label: 'Q1(a)', order: 0, max_marks: 2, answer_type: 'written', mcq_options: null, mark_scheme: {}, is_container: false, spec_ref: null, bounds: { x: 1, y: 2, w: 3, h: 4 }, page: 1 },
+      ],
+      response_areas: [
+        { id: 'r1', question_id: 'p1', template_id: 'tpl-1', page: 1, bounds: { x: 10, y: 20, w: 30, h: 40 }, kind: 'response', response_form: 'lines', source: 'manual', confirmed: true, confidence: null },
+        { id: 'f1', question_id: 'p1', template_id: 'tpl-1', page: 1, bounds: { x: 11, y: 21, w: 31, h: 41 }, kind: 'furniture', response_form: null, source: 'manual', confirmed: true, confidence: null },
+      ],
+      boundaries: [{ id: 'b1', template_id: 'tpl-1', question_id: 'q1', label: 'Q1 start', page_index: 0, y: 100, bounds: { x: 0, y: 100, w: 700, h: 8 }, source: 'manual', confirmed: true }],
+    })
+    expect(shapes.map((s) => s.kind).sort()).toEqual(['boundary', 'furniture', 'part', 'response'])
+    expect(shapes.find((s) => s.kind === 'part')).toMatchObject({ id: 'p1', x: 1, y: 2, w: 3, h: 4 })
+  })
+})

src/utils/exam-canvas/model.ts

@@ -0,0 +1,150 @@
+
+import type { ExamTemplateDetail, TemplateReplacePayload } from '../../types/exam.types'
+
+export const PAGE_HEIGHT = 1100
+export const PAGE_WIDTH = 780
+export const PAGE_GAP = 0
+
+export interface CanvasPageGeometry { pageNumber: number; x: number; y: number; w: number; h: number }
+
+export type ExamCanvasRegionKind = 'response' | 'context' | 'question_number' | 'mark_area' | 'reference' | 'furniture'
+export type ExamCanvasShapeKind = 'boundary' | 'part' | ExamCanvasRegionKind
+
+export interface CanvasBounds { x: number; y: number; w: number; h: number }
+
+export interface ExamCanvasShapeModel {
+  /** Stable domain UUID persisted to Supabase. Do not reuse tldraw shape ids for new shapes. */
+  id: string
+  kind: ExamCanvasShapeKind
+  x: number
+  y: number
+  w: number
+  h: number
+  label?: string
+  maxMarks?: number
+  answerType?: 'written' | 'mcq' | 'short' | 'diagram'
+  responseForm?: 'lines' | 'answer-box' | 'working' | 'diagram' | 'tick-boxes' | 'table' | 'blanks'
+  contextType?: string
+  questionId?: string | null
+}
+
+export function pageForY(y: number, pages?: CanvasPageGeometry[]): number {
+  if (pages?.length) {
+    const hit = pages.find((page) => y >= page.y && y <= page.y + page.h)
+    if (hit) return hit.pageNumber
+    const nearest = pages.reduce((best, page) => {
+      const dy = Math.min(Math.abs(y - page.y), Math.abs(y - (page.y + page.h)))
+      return dy < best.dy ? { page, dy } : best
+    }, { page: pages[0], dy: Number.POSITIVE_INFINITY })
+    return nearest.page.pageNumber
+  }
+  return Math.max(1, Math.floor(y / PAGE_HEIGHT) + 1)
+}
+
+export function pageTop(page: number, pages?: CanvasPageGeometry[]): number {
+  const hit = pages?.find((p) => p.pageNumber === page)
+  return hit?.y ?? ((page - 1) * (PAGE_HEIGHT + PAGE_GAP))
+}
+
+function pageForShape(shape: Pick<ExamCanvasShapeModel, 'y' | 'h'>, pages?: CanvasPageGeometry[]): number {
+  return pageForY(shape.y + shape.h / 2, pages)
+}
+
+export function isUuid(value: string | null | undefined): value is string {
+  return typeof value === 'string' && /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i.test(value)
+}
+
+export function newDomainId(): string {
+  if (typeof crypto !== 'undefined' && 'randomUUID' in crypto) {
+    return crypto.randomUUID()
+  }
+  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
+    const r = Math.floor(Math.random() * 16)
+    const v = c === 'x' ? r : (r % 4) + 8
+    return v.toString(16)
+  })
+}
+
+function bounds(shape: Pick<ExamCanvasShapeModel, 'x' | 'y' | 'w' | 'h'>): CanvasBounds {
+  return { x: shape.x, y: shape.y, w: shape.w, h: shape.h }
+}
+
+function contains(outer: CanvasBounds, inner: CanvasBounds): boolean {
+  const ox2 = outer.x + outer.w
+  const oy2 = outer.y + outer.h
+  const ix2 = inner.x + inner.w
+  const iy2 = inner.y + inner.h
+  return inner.x >= outer.x && inner.y >= outer.y && ix2 <= ox2 && iy2 <= oy2
+}
+
+function bandContains(top: ExamCanvasShapeModel, bottom: ExamCanvasShapeModel, shape: ExamCanvasShapeModel): boolean {
+  const minY = Math.min(top.y, bottom.y)
+  const maxY = Math.max(top.y, bottom.y)
+  const cy = shape.y + shape.h / 2
+  return cy >= minY && cy <= maxY
+}
+
+export function serializeCanvasShapes(template: ExamTemplateDetail, shapes: ExamCanvasShapeModel[], pages?: CanvasPageGeometry[]): TemplateReplacePayload {
+  const orderedBoundaries = shapes
+    .filter((s) => s.kind === 'boundary')
+    .sort((a, b) => (pageForShape(a, pages) - pageForShape(b, pages)) || (a.y - b.y))
+  const parts = shapes.filter((s) => s.kind === 'part')
+  const regions = shapes.filter((s) => s.kind !== 'boundary' && s.kind !== 'part')
+
+  const questions: TemplateReplacePayload['questions'] = []
+  const boundaries: TemplateReplacePayload['boundaries'] = []
+  const bands: Array<{ questionId: string; top: ExamCanvasShapeModel; bottom: ExamCanvasShapeModel }> = []
+
+  for (let i = 0; i < orderedBoundaries.length; i += 2) {
+    const top = orderedBoundaries[i]
+    const bottom = orderedBoundaries[i + 1]
+    if (!top || !bottom) break
+    const qNum = bands.length + 1
+    const questionId = isUuid(top.questionId) ? top.questionId : isUuid(bottom.questionId) ? bottom.questionId : newDomainId()
+    const label = top.label?.replace(/\s+(start|end)$/i, '') || bottom.label?.replace(/\s+(start|end)$/i, '') || `Q${qNum}`
+    questions.push({ id: questionId, label, order: qNum - 1, max_marks: 0, is_container: true, mark_scheme: {} })
+    bands.push({ questionId, top, bottom })
+    for (const b of [top, bottom]) {
+      boundaries.push({ id: isUuid(b.id) ? b.id : newDomainId(), question_id: questionId, label: b === top ? `${label} start` : `${label} end`, page_index: pageForShape(b, pages) - 1, y: b.y, bounds: bounds(b), source: 'manual', confirmed: true })
+    }
+  }
+
+  const partQuestionIds = new Map<string, string>()
+  parts.sort((a, b) => (a.y - b.y) || (a.x - b.x)).forEach((part, index) => {
+    const parentBand = bands.find((band) => bandContains(band.top, band.bottom, part))
+    const qid = isUuid(part.questionId) ? part.questionId : isUuid(part.id) ? part.id : newDomainId()
+    partQuestionIds.set(part.id, qid)
+    questions.push({ id: qid, parent_id: parentBand?.questionId ?? null, label: part.label || `Part ${index + 1}`, order: index, max_marks: Number(part.maxMarks ?? 0), answer_type: part.answerType ?? 'written', mcq_options: null, mark_scheme: {}, is_container: false, spec_ref: null, bounds: bounds(part), page: pageForShape(part, pages) })
+  })
+
+  const response_areas: TemplateReplacePayload['response_areas'] = []
+  for (const region of regions) {
+    const containingPart = parts.find((part) => contains(bounds(part), bounds(region)))
+    const fallbackPart = parts.find((part) => pageForShape(part, pages) === pageForShape(region, pages)) ?? parts[0]
+    const questionId = containingPart ? partQuestionIds.get(containingPart.id) : fallbackPart ? partQuestionIds.get(fallbackPart.id) : undefined
+    if (!questionId) continue
+    const kind = region.kind as ExamCanvasRegionKind
+    response_areas.push({ id: isUuid(region.id) ? region.id : newDomainId(), question_id: questionId, page: pageForShape(region, pages), bounds: bounds(region), kind, response_form: kind === 'response' ? (region.responseForm ?? 'lines') : null, context_type: kind === 'context' ? (region.contextType ?? 'generic') : null, source: 'manual', confirmed: true, confidence: null })
+  }
+
+  return { meta: { title: template.title, subject: template.subject ?? undefined, page_count: template.page_count ?? undefined, status: template.status }, questions, response_areas, boundaries }
+}
+
+export function shapesFromTemplate(detail: ExamTemplateDetail, pages?: CanvasPageGeometry[]): ExamCanvasShapeModel[] {
+  const shapes: ExamCanvasShapeModel[] = []
+  const questions = new Map(detail.questions.map((q) => [q.id, q]))
+  for (const b of detail.boundaries ?? []) {
+    const bb = b.bounds ?? { x: 48, y: b.y, w: PAGE_WIDTH - 96, h: 8 }
+    shapes.push({ id: b.id, kind: 'boundary', x: Number(bb.x ?? 48), y: Number(bb.y ?? b.y), w: Number(bb.w ?? PAGE_WIDTH - 96), h: Number(bb.h ?? 8), label: b.label ?? undefined, questionId: b.question_id })
+  }
+  for (const q of detail.questions ?? []) {
+    if (q.is_container || !q.bounds) continue
+    shapes.push({ id: q.id, kind: 'part', x: Number(q.bounds.x ?? 80), y: Number(q.bounds.y ?? 120), w: Number(q.bounds.w ?? 420), h: Number(q.bounds.h ?? 180), label: q.label, maxMarks: q.max_marks, answerType: q.answer_type ?? 'written', questionId: q.id })
+  }
+  for (const r of detail.response_areas ?? []) {
+    const bb = r.bounds ?? { x: 100, y: pageTop(r.page, pages) + 360, w: 360, h: 120 }
+    const q = questions.get(r.question_id)
+    shapes.push({ id: r.id, kind: r.kind, x: Number(bb.x ?? 100), y: Number(bb.y ?? pageTop(r.page, pages) + 360), w: Number(bb.w ?? 360), h: Number(bb.h ?? 120), label: q ? `→ ${q.label}` : r.kind, responseForm: r.response_form ?? undefined, contextType: r.context_type ?? undefined, questionId: r.question_id })
+  }
+  return shapes
+}