### Context & Goal

The current `web/src/server.ts` is a monolithic file with a very long `fetch` handler. This makes it difficult to read and maintain. Modularizing the logic into separate route handlers and middleware-like functions will improve code quality and scalability.

### Dependencies

- None

### Affected Files

- `web/src/server.ts`: Refactor to use modular handlers.
- `web/src/routes/api.ts`: New file for API route definitions.
- `web/src/routes/static.ts`: New file for static file serving logic.
- `web/src/routes/websocket.ts`: New file for WebSocket event handling.

### Technical Constraints & Strategy

- Implementation: Move different responsibilities (API, Static, WS) into separate files.
- The main `serve` configuration should just call these modules.
- Ensure the SPA fallback logic remains intact.

### Definition of Done (Binary)

- [ ] `web/src/server.ts` length reduced by at least 50%.
- [ ] API routes moved to dedicated module.
- [ ] Static file serving moved to dedicated module.
- [ ] WebSocket logic moved to dedicated module.
- [ ] Dashboard still loads and functions correctly.

### New Test Files

- None (Verification via manual testing of the dashboard).