[LOW] Enable TypeScript strict mode flags in backend tsconfig

[kilodesodiq-arch]

Engineering Gap

app/backend/tsconfig.json has noImplicitAny: false, strictBindCallApply: false, noFallthroughCasesInSwitch: false. These weaken TypeScript type safety. Frontend tsconfig has strict: true — backend lags behind.

Codebase Evidence

• app/backend/tsconfig.json lines 12-14: noImplicitAny: false, strictBindCallApply: false, noFallthroughCasesInSwitch: false
• app/frontend/tsconfig.json line 2: "strict": true

Risk Profile

Current Risk

Reduced type safety. Potential for implicit any bugs.

Business Impact

Lower code quality. More runtime type errors.

Remediation Strategy

Enable flags one at a time. Fix type errors incrementally. Start with noImplicitAny.

Success Conditions

• noImplicitAny enabled (or paths suppressed)
• strictBindCallApply enabled
• Build succeeds

Change Surface

File: app/backend/tsconfig.json

Security Review

Stricter types reduce injection and coercion bugs.

Completion Checklist

• Implementation completed
• Peer reviewed
• Build passing
• Ready for merge