feat(cis): add CCTranscriptionPanel Live tab to sidebar (Phase 1)

- Add CCTranscriptionPanel component with Live tab
- Add Zustand transcriptionStore for session state management
- Wire panel into BasePanel sidebar system
- Fix merged switch cases in getIconForPanel, getDescriptionForPanel, renderCurrentPanel
- Add VITE_WHISPERLIVE_URL to .env

src/utils/tldraw/ui-overrides/components/shared/BasePanel.tsx

@@ -23,7 +23,8 @@ import {
   Search as SearchIcon,
   Navigation as NavigationIcon,
   Save as NodeIcon,
-  Assignment as ExamIcon
+  Assignment as ExamIcon,
+  Mic as MicIcon
 } from '@mui/icons-material';
 import { CCShapesPanel } from './CCShapesPanel';
 import { CCSlidesPanel } from './CCSlidesPanel';
@@ -33,6 +34,7 @@ import { CCYoutubePanel } from './CCYoutubePanel';
 import { CCGraphPanel } from './CCGraphPanel';
 import { CCExamMarkerPanel } from './CCExamMarkerPanel';
 import { CCSearchPanel } from './CCSearchPanel'
+import { CCTranscriptionPanel } from './CCTranscriptionPanel'
 import { PANEL_DIMENSIONS, Z_INDICES } from './panel-styles';
 import './panel.css';
 // import { CCNavigationPanel } from './navigation/CCNavigationPanel';
@@ -47,6 +49,7 @@ export const PANEL_TYPES = {
     { id: 'node-snapshot', label: 'Node', order: 20 },
     { id: 'files', label: 'Files', order: 25 },
     { id: 'cc-shapes', label: 'Shapes', order: 30 },
+    { id: 'transcription', label: 'Transcription', order: 35 },
     { id: 'slides', label: 'Slides', order: 40 },
     { id: 'youtube', label: 'YouTube', order: 50 },
     { id: 'graph', label: 'Graph', order: 60 },
@@ -208,6 +211,8 @@ export const BasePanel: React.FC<BasePanelProps> = ({
         return <NavigationIcon />;
       case 'cc-shapes':
         return <ShapesIcon />;
+      case 'transcription':
+        return <MicIcon />;
       case 'slides':
         return <SlidesIcon />;
       case 'youtube':
@@ -231,6 +236,8 @@ export const BasePanel: React.FC<BasePanelProps> = ({
     switch (panelId) {
       case 'cabinets':
         return 'Manage file cabinets';
+      case 'transcription':
+        return 'Record and transcribe lessons';
       case 'cc-shapes':
         return 'Add shapes and elements to your canvas';
       case 'slides':
@@ -260,6 +267,8 @@ export const BasePanel: React.FC<BasePanelProps> = ({
     switch (currentPanelType) {
       case 'cabinets':
         return <CCCabinetsPanel />;
+      case 'transcription':
+        return <CCTranscriptionPanel />;
       case 'files':
         return <CCFilesPanel />;
       case 'cc-shapes':