Enable noUncheckedIndexedAccess in app tsconfigs

Problem¶

Shared packages (widget-wire-schemas, widget-renderers, portable-text) already set noUncheckedIndexedAccess: true, but the apps' tsconfigs do not. This means arr[i] and map.get(k) are inferred as their element type with no | undefined, hiding a class of runtime bugs.

• apps/cms/tsconfig.json — strict, but missing noUncheckedIndexedAccess.
• apps/lms/tsconfig.json — same gap.

Proposal¶

1. Enable noUncheckedIndexedAccess: true in both app tsconfigs.
2. Run npm run typecheck and fix fallout iteratively. Expected hotspots:
   • Pagination helpers slicing arrays.
   • Map-based RBAC lookups in apps/cms/src/lib/rbac/*.
   • Kysely result destructuring (rows[0]).
3. Use explicit guards (if (!row) throw ...) rather than non-null assertions where possible. Where a non-null assertion is genuinely correct, add a brief comment explaining why.
4. Do not introduce // @ts-expect-error to silence failures.

Acceptance criteria¶

• noUncheckedIndexedAccess: true set in both app tsconfigs (and packages/ui).
• npm run typecheck is green for both apps.
• No new // @ts-ignore / // @ts-expect-error added.
• npm run check passes.

Out of scope¶

• Tightening other strictness flags (exactOptionalPropertyTypes, noPropertyAccessFromIndexSignature).
• Refactoring code beyond what the new check forces.

Notes / decisions log¶

• 2026-05-24: Ticket created from monorepo audit.
• 2026-05-25: Implemented bundled with T-008: enabled flag on apps/lms, apps/cms, and packages/ui; fixed ~58 LMS and ~393 CMS indexed-access errors; added shared getInitials at @open-learning-hub/ui/lib/get-initials; CMS test helpers (src/test/expect-defined.ts, kysely-chain-mock.ts, store-test-helpers.ts). Re-rated effort medium (CMS Zustand stores + test fixtures dominated lift).