[Wave 200pts] FIX: main.ts declares the same `const port` variable twice in the same function scope, a compile error

[portableDD]

Summary

src/main.ts's bootstrap() function declares const port = configService.get<number>('app.port'); twice — once near the top (used immediately for the isNaN(port) validation check) and again, identically, right before await app.listen(port) near the end of the same function. This is a duplicate block-scoped variable declaration in the same scope, which TypeScript rejects outright (Cannot redeclare block-scoped variable 'port').

Why This Matters

main.ts is the application's actual entry point — a compile error here means nest build/npm run start cannot produce a runnable application at all, independent of every other syntax error found elsewhere in the codebase. This is a small, easy fix, but it is a genuine, currently-committed blocker to booting the app even after every other file-level syntax error is resolved.

What Needs to Be Done

• Remove the second const port = ... declaration near the end of bootstrap() and reuse the port variable already declared and validated earlier in the function for the app.listen(port) call.
• Re-run npx tsc --noEmit against main.ts to confirm no redeclaration error remains.
• Add the file to whatever CI build/typecheck step is introduced to catch this class of error going forward.

Key Files

• src/main.ts (both const port = configService.get<number>('app.port'); declarations)

Acceptance Criteria

• port is declared exactly once in bootstrap()
• npx tsc --noEmit reports no redeclaration error for main.ts
• The application still validates the port (throws on NaN/falsy) and listens on the correct port after the fix

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Points: 200
Category: FIX