Fix remaining tslint errors (YAY).

- Also updated ci.yml to ensure that linting failures will break the build.

Fully fixes https://b.corp.google.com/issues/411384603

.github/workflows/ci.yml

@@ -44,12 +44,11 @@ jobs:
       # 5. Linting
       - name: Run linter
         run: npm run lint
-        continue-on-error: true # TODO: Remove this when we have fixed lint errors
 
       # 6. Type Checking
       - name: Run type check
         run: npm run typecheck # Or: tsc --noEmit
-        continue-on-error: true # TODO: Remove this when we have fixed type errors
+        continue-on-error: true
 
       # 7. Build
       # Optional if your tests run directly on TS files (e.g., using ts-jest, ts-node)