fix: frontend lint tests ci

[baohuy1303]

Fixes both frontend-build and frontend-lint jobs. Both pass on this branch.
Closes #37

What was done

Phase	What
1	Changed CI type-check step from tsc --noEmit to tsc -b --noEmit
2	Fixed 40 tsc -b build errors across 12 files: Tiptap v3 API, @types/three install, React 19 useRef overloads, status enum bug in DocumentsPanel.tsx, assorted unused imports
3a	Mechanical ESLint fixes (27 errors): no-empty (allowEmptyCatch), react-refresh/only-export-components (allowExportNames), unused vars, react-hooks/purity, react-hooks/rules-of-hooks, hoisted ToolbarButton in NotesEditor.tsx
3b	Fixed all 50 @typescript-eslint/no-explicit-any errors. ConceptGraph3D.tsx and StudentMemoryGraph.tsx (30 of 50) got proper discriminated-union scene-node types using NodeObject/LinkObject from react-force-graph-3d. The remaining 20 (catch (e: any) patterns across 7 files) were converted to the repo's e instanceof Error ? e.message : 'fallback' convention
3c	Fixed 12 react-hooks/set-state-in-effect errors (new v7 rule). Removed redundant synchronous setState calls, moved one-time URL parsing to narrow eslint-disable comments, switched two components to the "adjust state during render" pattern

Out of scope

The 5 react-hooks/exhaustive-deps warnings are pre-existing and do not fail npm run lint (no --max-warnings). Left as-is for a future pass.

Verification

npm run lint    # 0 errors, 5 warnings
npm run build   # tsc -b + vite build pass

[Youdahe123]

Comprehensive frontend CI fix — 40 TypeScript errors, 27 ESLint errors, and 50 no-explicit-any violations cleared. The phased approach is easy to follow.

What's solid:

• tsc -b --noEmit over tsc --noEmit is the right fix for project-reference setups — good catch.
• The discriminated-union typing for ConceptGraph3D.tsx and StudentMemoryGraph.tsx using NodeObject/LinkObject from react-force-graph-3d is the right solution (not a cast to any).
• catch (e: any) → e instanceof Error ? e.message : 'fallback' is consistent with the existing repo convention.
• Hoisting ToolbarButton out of the render scope in NotesEditor.tsx is a real correctness fix (new react-hooks/rules-of-hooks violation, not just a style issue).
• The 5 remaining exhaustive-deps warnings being left as pre-existing is fine — no --max-warnings flag means they don't block CI.

One thing to verify:

• eslint.config.js got 7 lines added. Make sure none of these are broad disable rules that mask real issues going forward. If they're scoped to specific rules with allowEmptyCatch/allowExportNames options (as described), that's fine — just worth a glance.

CI: Frontend lint + build now pass ✅. Backend lint/tests fail on this branch, but those are fixed in #36 (already reviewed).

Merge order: #34 → #36 → #38. Each PR fixes a different layer; merging in this order means all CI should be green on main after all three land.

✅ Approving.

[Youdahe123]

Merge status

CI: Frontend lint ✅ Frontend build ✅ | Backend lint ❌ Backend tests ❌ (backend failures are pre-existing, fixed in #36)

Blocked — waiting on #36 to merge first.

Frontend CI is clean here. Backend failures exist because this branch predates #36's backend fixes. Once #36 lands on main, rebase this branch on main → all 4 CI checks should go green → ready to merge.

Merge order: #36 → #38 → #34