# Task ID: 43

**Title:** Add regenerate-summary API endpoint

**Status:** done

**Dependencies:** 42 ✓

**Priority:** medium

**Description:** Create POST /api/v1/prompts/:id/regenerate-summary endpoint to force re-generation of summary and chapters for a prompt.

**Details:**

1. Add route in `/src/mcpd/src/routes/prompts.ts`:
   ```typescript
   fastify.post('/api/v1/prompts/:id/regenerate-summary', async (request, reply) => {
     const { id } = request.params as { id: string };
     const prompt = await promptService.findById(id);
     if (!prompt) {
       return reply.status(404).send({ error: 'Prompt not found' });
     }
     
     const { summary, chapters } = await summaryService.generateSummary(prompt.content);
     const updated = await promptService.updateSummary(id, summary, chapters);
     
     return reply.send(updated);
   });
   ```

2. Add `updateSummary(id, summary, chapters)` method to PromptRepository and PromptService

3. Return the updated prompt with new summary/chapters in response

**Test Strategy:**

- Unit test: POST to valid prompt ID regenerates summary
- Unit test: Returns updated prompt with new summary/chapters
- Unit test: 404 for non-existent prompt ID
- Unit test: Uses LLM when available, regex fallback otherwise
- Integration test: End-to-end regeneration updates database