🔧 Fix TypeScript strict mode errors

[jobbykings]

Summary

Enabling TypeScript strict mode reveals numerous type errors that should be fixed to improve code quality.

Tasks

• Enable strict: true in tsconfig.json
• Fix all resulting type errors
• Add noUncheckedIndexedAccess and exactOptionalPropertyTypes
• Update CI to fail on type errors

Acceptance Criteria

• tsc --noEmit passes with strict mode enabled
• No any types introduced as workarounds