Enforce strict Oxlint policy

[jasonhedman]

Summary

• enable typescript/no-deprecated and fail on stale lint suppressions
• remove the blanket JavaScript and application/AI Elements lint exemptions
• enable unassigned-import, await-in-loop, shadowing, map-spread, array-index-key, consistent-return, function-scoping, and immutable-sort checks
• fix the resulting type-safety, async, accessibility, React, Tailwind, and control-flow violations
• convert the development supervisor to TypeScript so it receives the full type-aware lint policy
• retain only narrow, documented exceptions for sequential loops, runtime images, generated shadcn code, and package-provided AI Elements Tailwind utilities

Verification

• pnpm check (0 lint warnings/errors; 214 tests passed; typecheck, formatting, Knip, and boundaries passed)
• pnpm build (with documented local database URL and auth origin placeholders)