Mode-3: Question bank page + custom-paper assembly UI

New /exam-marker/bank page: browse leaf questions across your papers, filter by
spec point (the spec-planning surface) and subject via facet chips, select
questions into a basket, and "Create paper" → POST /custom-papers → opens the new
template in setup. Dashboard gets a "Question bank" entry point.

examRepository.getBank + createCustomPaper; BankQuestion/BankResponse/custom-paper
types. tsc clean. Pairs with the mode-3 API endpoints (already merged).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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, ExamMarkingPage, ExamResultsPage, ExamTemplateSetupPage, MarkSchemePage } from './pages/exam';
+import { ExamDashboardPage, ExamMarkingPage, ExamResultsPage, ExamTemplateSetupPage, MarkSchemePage, QuestionBankPage } from './pages/exam';
 import { ErrorBoundary } from './components/ErrorBoundary';
 import CalendarPage from './pages/user/calendarPage';
 import SettingsPage from './pages/user/settingsPage';
@@ -184,6 +184,7 @@ 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/bank" element={<ErrorBoundary><QuestionBankPage /></ErrorBoundary>} />
             <Route path="/exam-marker/:templateId/setup" element={<ErrorBoundary><ExamTemplateSetupPage /></ErrorBoundary>} />
             <Route path="/exam-marker/:templateId/marks" element={<ErrorBoundary><MarkSchemePage /></ErrorBoundary>} />
             <Route path="/exam-marker/:batchId/mark" element={<ErrorBoundary><ExamMarkingPage /></ErrorBoundary>} />

src/pages/exam/ExamDashboardPage.tsx

@@ -25,6 +25,7 @@ import AssignmentIcon from '@mui/icons-material/Assignment';
 import ContentCopyIcon from '@mui/icons-material/ContentCopy';
 import EditIcon from '@mui/icons-material/Edit';
 import GradingIcon from '@mui/icons-material/Grading';
+import PlaylistAddCheckIcon from '@mui/icons-material/PlaylistAddCheck';
 
 import { useAuth } from '../../contexts/AuthContext';
 import { examRepository } from '../../services/exam/examRepository';
@@ -233,9 +234,14 @@ const ExamDashboardPage: React.FC = () => {
               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={openCreate}>
-            New template
-          </Button>
+          <Stack direction="row" spacing={1}>
+            <Button variant="outlined" startIcon={<PlaylistAddCheckIcon />} onClick={() => navigate('/exam-marker/bank')}>
+              Question bank
+            </Button>
+            <Button variant="contained" startIcon={<AddIcon />} onClick={openCreate}>
+              New template
+            </Button>
+          </Stack>
         </Box>
 
         {error && (

src/pages/exam/QuestionBankPage.tsx

@@ -0,0 +1,185 @@
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
+import { useNavigate } from 'react-router-dom';
+import {
+  Alert, Box, Button, Card, CardActionArea, CardContent, Chip, CircularProgress, Container,
+  Dialog, DialogActions, DialogContent, DialogTitle, Stack, TextField, Typography,
+} from '@mui/material';
+import ArrowBackIcon from '@mui/icons-material/ArrowBack';
+import PlaylistAddCheckIcon from '@mui/icons-material/PlaylistAddCheck';
+import CheckCircleIcon from '@mui/icons-material/CheckCircle';
+import RadioButtonUncheckedIcon from '@mui/icons-material/RadioButtonUnchecked';
+
+import { examRepository } from '../../services/exam/examRepository';
+import type { BankQuestion, BankResponse } from '../../types/exam.types';
+
+const QuestionBankPage: React.FC = () => {
+  const navigate = useNavigate();
+  const [bank, setBank] = useState<BankResponse | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [specRef, setSpecRef] = useState<string | null>(null);
+  const [subject, setSubject] = useState<string | null>(null);
+  const [selected, setSelected] = useState<Set<string>>(new Set());
+  const [dialogOpen, setDialogOpen] = useState(false);
+  const [title, setTitle] = useState('');
+  const [creating, setCreating] = useState(false);
+
+  const load = useCallback(async () => {
+    setLoading(true); setError(null);
+    try {
+      setBank(await examRepository.getBank({ specRef: specRef ?? undefined, subject: subject ?? undefined }));
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+    } finally {
+      setLoading(false);
+    }
+  }, [specRef, subject]);
+
+  useEffect(() => { void load(); }, [load]);
+
+  const toggle = (id: string) => setSelected((prev) => {
+    const next = new Set(prev);
+    if (next.has(id)) next.delete(id); else next.add(id);
+    return next;
+  });
+
+  const selectedList = useMemo(() => Array.from(selected), [selected]);
+  const selectedQuestions = useMemo(
+    () => (bank?.questions ?? []).filter((q) => selected.has(q.id)),
+    [bank, selected],
+  );
+  const totalMarks = selectedQuestions.reduce((s, q) => s + (q.max_marks ?? 0), 0);
+
+  // facet lists (sorted) with counts
+  const specFacets = Object.entries(bank?.facets.spec_ref ?? {}).sort((a, b) => (a[0] < b[0] ? -1 : 1));
+  const subjectFacets = Object.entries(bank?.facets.subject ?? {}).sort((a, b) => (a[0] < b[0] ? -1 : 1));
+
+  const create = async () => {
+    setCreating(true); setError(null);
+    try {
+      const subj = subject ?? selectedQuestions[0]?.paper.subject ?? undefined;
+      const res = await examRepository.createCustomPaper({
+        title: title.trim() || `Custom paper — ${new Date().toISOString().slice(0, 10)}`,
+        subject: subj ?? undefined,
+        question_ids: selectedList,
+      });
+      navigate(`/exam-marker/${res.id}/setup`);
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+      setCreating(false);
+      setDialogOpen(false);
+    }
+  };
+
+  return (
+    <Container maxWidth="lg" sx={{ py: 4 }}>
+      <Button size="small" startIcon={<ArrowBackIcon />} onClick={() => navigate('/exam-marker')} sx={{ mb: 1 }}>
+        Exam Marker
+      </Button>
+      <Box sx={{ display: 'flex', alignItems: 'flex-start', justifyContent: 'space-between', gap: 2, flexWrap: 'wrap', mb: 2 }}>
+        <Box>
+          <Typography variant="h4" component="h1" fontWeight={700}>Question bank</Typography>
+          <Typography variant="body2" color="text.secondary">
+            Plan by spec point, then assemble a custom paper from questions across your papers.
+          </Typography>
+        </Box>
+        <Button
+          variant="contained"
+          startIcon={<PlaylistAddCheckIcon />}
+          disabled={selected.size === 0}
+          onClick={() => setDialogOpen(true)}
+        >
+          Create paper ({selected.size}{totalMarks ? ` · ${totalMarks}m` : ''})
+        </Button>
+      </Box>
+
+      {error && <Alert severity="error" sx={{ mb: 2 }} onClose={() => setError(null)}>{error}</Alert>}
+
+      {/* Filters */}
+      <Stack spacing={1} sx={{ mb: 2 }}>
+        <Stack direction="row" spacing={0.75} alignItems="center" flexWrap="wrap" useFlexGap>
+          <Typography variant="caption" color="text.secondary" sx={{ mr: 0.5 }}>Spec point:</Typography>
+          <Chip size="small" label="all" color={specRef ? 'default' : 'primary'} onClick={() => setSpecRef(null)} variant={specRef ? 'outlined' : 'filled'} />
+          {specFacets.map(([ref, count]) => (
+            <Chip key={ref} size="small" label={`${ref} · ${count}`} color={specRef === ref ? 'primary' : 'default'} variant={specRef === ref ? 'filled' : 'outlined'} onClick={() => setSpecRef(ref)} />
+          ))}
+        </Stack>
+        {subjectFacets.length > 1 && (
+          <Stack direction="row" spacing={0.75} alignItems="center" flexWrap="wrap" useFlexGap>
+            <Typography variant="caption" color="text.secondary" sx={{ mr: 0.5 }}>Subject:</Typography>
+            <Chip size="small" label="all" color={subject ? 'default' : 'secondary'} onClick={() => setSubject(null)} variant={subject ? 'outlined' : 'filled'} />
+            {subjectFacets.map(([s, count]) => (
+              <Chip key={s} size="small" label={`${s} · ${count}`} color={subject === s ? 'secondary' : 'default'} variant={subject === s ? 'filled' : 'outlined'} onClick={() => setSubject(s)} sx={{ textTransform: 'capitalize' }} />
+            ))}
+          </Stack>
+        )}
+      </Stack>
+
+      {loading ? (
+        <Box sx={{ display: 'flex', justifyContent: 'center', py: 6 }}><CircularProgress /></Box>
+      ) : (bank?.questions.length ?? 0) === 0 ? (
+        <Alert severity="info">
+          No questions match yet. Questions appear here once your templates have parts with spec points
+          (set them in the mark-scheme editor). Auto-map + confirm on a paper to populate it.
+        </Alert>
+      ) : (
+        <>
+          <Typography variant="body2" color="text.secondary" sx={{ mb: 1 }}>
+            {bank?.n} question{bank?.n === 1 ? '' : 's'} · click to add to your paper
+          </Typography>
+          <Box sx={{ display: 'grid', gridTemplateColumns: { xs: '1fr', sm: '1fr 1fr', md: '1fr 1fr 1fr' }, gap: 1.5 }}>
+            {(bank?.questions ?? []).map((q: BankQuestion) => {
+              const on = selected.has(q.id);
+              return (
+                <Card key={q.id} variant="outlined" sx={{ borderColor: on ? 'primary.main' : 'divider', borderWidth: on ? 2 : 1 }}>
+                  <CardActionArea onClick={() => toggle(q.id)}>
+                    <CardContent sx={{ pb: 1.5 }}>
+                      <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', mb: 0.5 }}>
+                        <Typography variant="subtitle2" fontWeight={700}>Q{q.label ?? '?'}</Typography>
+                        {on ? <CheckCircleIcon color="primary" fontSize="small" /> : <RadioButtonUncheckedIcon color="disabled" fontSize="small" />}
+                      </Box>
+                      <Stack direction="row" spacing={0.5} flexWrap="wrap" useFlexGap sx={{ mb: 0.75 }}>
+                        <Chip size="small" label={`${q.max_marks ?? 0} marks`} />
+                        {q.answer_type && <Chip size="small" variant="outlined" label={q.answer_type} />}
+                        {q.spec_ref && <Chip size="small" color="info" label={q.spec_ref} />}
+                      </Stack>
+                      <Typography variant="caption" color="text.secondary" noWrap sx={{ display: 'block', textTransform: 'capitalize' }}>
+                        {[q.paper.subject, q.paper.title].filter(Boolean).join(' · ') || 'Untitled paper'}
+                      </Typography>
+                    </CardContent>
+                  </CardActionArea>
+                </Card>
+              );
+            })}
+          </Box>
+        </>
+      )}
+
+      <Dialog open={dialogOpen} onClose={() => !creating && setDialogOpen(false)} fullWidth maxWidth="sm">
+        <DialogTitle>Create custom paper</DialogTitle>
+        <DialogContent>
+          <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
+            {selected.size} question{selected.size === 1 ? '' : 's'} · {totalMarks} marks. This creates a new
+            template you can open in setup and use for marking.
+          </Typography>
+          <TextField
+            autoFocus
+            fullWidth
+            label="Paper title"
+            value={title}
+            onChange={(e) => setTitle(e.target.value)}
+            placeholder={`Custom paper — ${new Date().toISOString().slice(0, 10)}`}
+          />
+        </DialogContent>
+        <DialogActions>
+          <Button onClick={() => setDialogOpen(false)} disabled={creating}>Cancel</Button>
+          <Button variant="contained" onClick={create} disabled={creating} startIcon={creating ? <CircularProgress size={16} color="inherit" /> : undefined}>
+            {creating ? 'Creating…' : 'Create & open'}
+          </Button>
+        </DialogActions>
+      </Dialog>
+    </Container>
+  );
+};
+
+export default QuestionBankPage;

src/pages/exam/index.ts

@@ -1,4 +1,5 @@
 export { default as ExamDashboardPage } from './ExamDashboardPage';
+export { default as QuestionBankPage } from './QuestionBankPage';
 export { default as ExamTemplateSetupPage } from './setup/ExamTemplateSetupPage';
 export { default as MarkSchemePage } from './MarkSchemePage';
 export { default as ExamMarkingPage } from './ExamMarkingPage';

src/services/exam/examRepository.ts

@@ -13,9 +13,12 @@ import { supabase } from '../../supabaseClient';
 import type {
   AutoMapJobStatus,
   AutoMapResponse,
+  BankResponse,
   BatchQueueResponse,
   BatchResultsResponse,
   CreateBatchPayload,
+  CreateCustomPaperPayload,
+  CreateCustomPaperResult,
   CreateTemplatePayload,
   ExamBoundary,
   ExamQuestion,
@@ -300,6 +303,21 @@ export const examRepository = {
     return res.data;
   },
 
+  async getBank(params: { specRef?: string; subject?: string } = {}): Promise<BankResponse> {
+    const headers = await authHeaders();
+    const res = await axios.get<BankResponse>(`${EXAM_BASE}/bank`, {
+      headers,
+      params: { spec_ref: params.specRef, subject: params.subject },
+    });
+    return res.data;
+  },
+
+  async createCustomPaper(payload: CreateCustomPaperPayload): Promise<CreateCustomPaperResult> {
+    const headers = await authHeaders();
+    const res = await axios.post<CreateCustomPaperResult>(`${EXAM_BASE}/custom-papers`, payload, { headers });
+    return res.data;
+  },
+
   async uploadScan(
     batchId: string,
     file: File,

src/types/exam.types.ts

@@ -338,3 +338,36 @@ export interface MarkUpsertPayload {
   comment?: string;
   confirmed?: boolean;
 }
+
+// ── Mode-3 question bank + custom-paper assembly ──────────────────────────────
+export interface BankQuestion {
+  id: string;
+  template_id: string;
+  label: string | null;
+  max_marks: number | null;
+  answer_type: string | null;
+  spec_ref: string | null;
+  bounds: Record<string, number> | null;
+  page: number | null;
+  paper: { id: string | null; title: string | null; subject: string | null; exam_code: string | null };
+}
+
+export interface BankResponse {
+  questions: BankQuestion[];
+  n: number;
+  facets: { spec_ref: Record<string, number>; subject: Record<string, number> };
+}
+
+export interface CreateCustomPaperPayload {
+  title: string;
+  subject?: string;
+  question_ids: string[];
+}
+
+export interface CreateCustomPaperResult {
+  id: string;
+  title: string;
+  subject: string | null;
+  n_questions: number;
+  n_response_areas: number;
+}