Fix TypeScript linting issues and test failures

- Replace 37 instances of 'any' type with proper TypeScript types
- Fix trailing spaces in i18n.test.ts
- Add proper interfaces for profanity analysis and matches
- Extend Express Request interface with custom properties
- Fix error handling in ProfanityFilterService for constraint violations
- Update test mocks to satisfy TypeScript strict checking
- All 147 tests now pass with 0 linting errors

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

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

tests/unit/services/ProfanityFilterService.test.ts

@@ -165,7 +165,7 @@ describe('ProfanityFilterService', () => {
     it('should remove custom words', async () => {
       const added = await profanityFilter.addCustomWord('removeme', 'low', 'test');
 
-      const result = await profanityFilter.removeCustomWord(added.id);
+      const result = await profanityFilter.removeCustomWord(added.id!);
 
       expect(result.deleted).toBe(true);
       expect(result.changes).toBe(1);
@@ -181,7 +181,7 @@ describe('ProfanityFilterService', () => {
     it('should update custom words', async () => {
       const added = await profanityFilter.addCustomWord('updateme', 'low', 'test');
 
-      const result = await profanityFilter.updateCustomWord(added.id, {
+      const result = await profanityFilter.updateCustomWord(added.id!, {
         word: 'updated',
         severity: 'high',
         category: 'updated'