Add comprehensive TypeScript support and conversion

- Convert entire backend to TypeScript with strict type checking
- Add comprehensive type definitions and interfaces
- Create typed models for Location and ProfanityWord with database operations
- Convert all services to TypeScript (DatabaseService, ProfanityFilterService)
- Convert all API routes with proper request/response typing
- Add TypeScript build system and development scripts
- Update package.json with TypeScript dependencies and scripts
- Configure tsconfig.json with strict typing and build settings
- Update CLAUDE.md documentation for TypeScript development
- Add .gitignore rules for TypeScript build artifacts

Architecture improvements:
- Full type safety throughout the application
- Typed database operations and API endpoints
- Proper error handling with typed exceptions
- Strict optional property handling
- Type-safe dependency injection for routes

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

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

CLAUDE.md

@@ -9,18 +9,31 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 # Install dependencies
 npm install
 
-# Start the server (production mode)
+# Start the server (production mode - TypeScript)
 npm start
 
-# Start with auto-reload (development mode)
-npm run dev
-
-# Development with CSS watching (recommended for frontend work)
-npm run dev-with-css
+# Development mode options:
+npm run dev           # TypeScript development with auto-reload
+npm run dev:js        # Legacy JavaScript development mode
+npm run dev-with-css:ts  # TypeScript + CSS watching (recommended)
+npm run dev-with-css     # Legacy JS + CSS watching
 ```
 
 The application runs on port 3000 by default. Visit http://localhost:3000 to view the website.
 
+### TypeScript Development
+The backend is written in TypeScript and compiles to `dist/` directory.
+```bash
+# Build TypeScript (production)
+npm run build:ts
+
+# Build everything (TypeScript + CSS)
+npm run build
+
+# Development with TypeScript watching
+npm run dev:ts
+```
+
 ### CSS Development
 CSS is generated from SCSS and should NOT be committed to git.
 ```bash
@@ -57,19 +70,27 @@ Required environment variables:
 
 ## Architecture Overview
 
-### Backend (Node.js/Express)
-- **server.js**: Main Express server with modular route architecture
+### Backend (Node.js/Express + TypeScript)
+- **src/server.ts**: Main Express server with modular route architecture (compiles to `dist/server.js`)
   - Uses two SQLite databases: `icewatch.db` (locations) and `profanity.db` (content moderation)
   - Automatic cleanup of reports older than 48 hours via node-cron
   - Bearer token authentication for admin endpoints
   - Environment variable configuration via dotenv
+  - Full TypeScript with strict type checking
 
 ### Route Architecture
-Routes are organized as factory functions accepting dependencies:
+Routes are organized as factory functions accepting dependencies with full TypeScript typing:
 
-- **routes/config.js**: Public API configuration endpoints
-- **routes/locations.js**: Location submission and retrieval with profanity filtering
-- **routes/admin.js**: Admin panel functionality with authentication middleware
+- **src/routes/config.ts**: Public API configuration endpoints
+- **src/routes/locations.ts**: Location submission and retrieval with profanity filtering
+- **src/routes/admin.ts**: Admin panel functionality with authentication middleware
+
+### Models & Services (TypeScript)
+- **src/models/Location.ts**: Type-safe database operations for location data
+- **src/models/ProfanityWord.ts**: Type-safe database operations for profanity words
+- **src/services/DatabaseService.ts**: Centralized database connection management
+- **src/services/ProfanityFilterService.ts**: Content moderation with type safety
+- **src/types/index.ts**: Shared TypeScript interfaces and type definitions
 
 ### Database Schema
 **Main Database (`icewatch.db`)**:
@@ -131,11 +152,13 @@ SCSS files are in `src/scss/`:
 
 ### Key Design Patterns
 
-1. **Modular Route Architecture**: Routes accept dependencies as parameters for testability
-2. **Dual Database Design**: Separate databases for application data and content moderation
-3. **Graceful Degradation**: Fallback geocoding providers and error handling
-4. **Automated Maintenance**: Cron-based cleanup of expired reports
-5. **Security**: Server-side content filtering, environment-based configuration
+1. **TypeScript-First Architecture**: Full type safety with strict type checking
+2. **Modular Route Architecture**: Routes accept dependencies as parameters for testability
+3. **Dual Database Design**: Separate databases for application data and content moderation
+4. **Type-Safe Database Operations**: All database interactions use typed models
+5. **Graceful Degradation**: Fallback geocoding providers and error handling
+6. **Automated Maintenance**: Cron-based cleanup of expired reports
+7. **Security**: Server-side content filtering, environment-based configuration
 
 ### Deployment
 - Automated deployment script for Debian 12 ARM64 in `scripts/deploy.sh`