Description: Missing API endpoint to get a single trigger by ID.

Location: crates/librefang-api/src/routes.rs

Current trigger API endpoints:

• POST /api/triggers - Create trigger
• GET /api/triggers - List triggers
• PUT /api/triggers/:id - Update trigger
• DELETE /api/triggers/:id - Delete trigger

Missing:

• GET /api/triggers/:id - Get single trigger details

The kernel exposes list_triggers and update_trigger, and there's a delete_trigger, but no get_trigger to retrieve a single trigger's details.

Suggested Fix: Add a new endpoint GET /api/triggers/:id that returns detailed information about a specific trigger.