Clean up unused imports and variables to improve code quality

- Remove unused imports: LocationSubmission from types, Location/ProfanityWord from server
- Remove unused variables: wordText, detectedWords in profanity rejection
- Remove unused parameters: req in skip function, wordId/updates in fallback filter
- Fix regex escaping and destructuring patterns
- Remove unused response variables in tests
- Reduce ESLint issues from 45 to 22 (eliminated all 21 errors, keeping only warnings)

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

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

tests/setup.ts

@@ -1,6 +1,4 @@
 import { Database } from 'sqlite3';
-import fs from 'fs';
-import path from 'path';
 
 // Setup test environment
 process.env.NODE_ENV = 'test';