Docker baseline before Phase 6 modernization

🔄 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/tsconfig.json

@@ -18,7 +18,11 @@
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "noImplicitReturns": true,
-    "noFallthroughCasesInSwitch": true
+    "noFallthroughCasesInSwitch": true,
+    "exactOptionalPropertyTypes": true,
+    "noImplicitOverride": true,
+    "noPropertyAccessFromIndexSignature": true,
+    "noUncheckedIndexedAccess": true
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "dist", "**/*.test.ts"]