feat: implement external API integration with static tide tables (task 32)

- Add in-memory caching for external API responses (6-hour expiration)
- Implement OpenWeatherMap integration for weather data
- Create static tide tables for 22 Irish coastal stations
- Add tide calculation based on semi-diurnal patterns and lunar cycles
- Implement water quality, beach quality, and biodiversity placeholder endpoints
- Add comprehensive API documentation (EXTERNAL_API_SETUP.md)
- Fix frontend WaterQualityIndicator crash
- Remove Redis dependency (using in-memory cache instead)
- All external data endpoints functional and tested

server/src/index.ts

@@ -6,6 +6,7 @@ import path from 'path';
 import reportRoutes from './routes/reportRoutes';
 import eventRoutes from './routes/eventRoutes';
 import userRoutes from './routes/userRoutes';
+import externalDataRoutes from './routes/externalDataRoutes';
 
 // Load environment variables
 dotenv.config();
@@ -42,6 +43,7 @@ app.get('/health', (req, res) => {
 app.use('/api/reports', reportRoutes);
 app.use('/api/events', eventRoutes);
 app.use('/api/users', userRoutes);
+app.use('/api/external', externalDataRoutes);
 
 // Error handling middleware
 app.use((err: any, req: express.Request, res: express.Response, next: express.NextFunction) => {