chore(ci/build): typecheck gate, npm ci, backend CI, dep+vuln fixes, hygiene

Audit remediation (build/supply-chain/quality):
- Add `@pezkuwi/api-augment` import in main.tsx -> tsc errors 416->328 (Codec-typed
  on-chain reads now augmented); add `typecheck` script + a non-blocking Typecheck CI
  step (flip to blocking once errors reach 0).
- CI: `npm install` -> `npm ci` (lockfile enforced) in web + security-audit jobs; add a
  Backend Indexer job (npm ci + node --check + non-blocking high/critical audit). No
  live tests run in CI (they need a live chain) — a mockable CI test subset is a
  follow-up.
- Vulns: bump dompurify ^3.4.12 + postcss ^8.5.23 (web prod highs cleared; only the
  react-router v7 open-redirect remains, deferred as a breaking major); backend tar
  ^7.5.22 + ws ^8.21.1 (clears the critical tar advisory). Lockfiles regenerated.
- Prod build now drops console/debugger (vite esbuild.drop); NotificationBell realtime
  subscription now returns cleanup + uses a per-user channel (fixes leak); ProfileSettings
  language codes aligned to i18n config (ku-kurmanji/ku-sorani).
- Root package.json sdk-ui path env-driven (${SDK_UI_DIR}); generate-docs rustup path
  resolved dynamically; Docker image license label MIT (matches LICENSE). Removed scratch
  files (mimari.txt, _scratch_credit_serok.mjs).

web/Dockerfile

@@ -49,5 +49,5 @@ WORKDIR /dist
 COPY --from=builder /build/web/dist /dist
 LABEL org.opencontainers.image.source="https://github.com/pezkuwichain/pwap"
 LABEL org.opencontainers.image.description="pwap/web static SPA — Pezkuwi wallet/exchange frontend"
-LABEL org.opencontainers.image.licenses="proprietary"
+LABEL org.opencontainers.image.licenses="MIT"
 CMD ["sh", "-c", "echo 'pwap-web image — extract /dist via: docker create + docker cp'; sleep infinity"]