Implement /compact endpoint for database optimization

[clafollett]

Description

Implement the /compact endpoint to optimize database storage and improve query performance.

Current State

• No implementation
• Defined in OpenAPI spec

Acceptance Criteria

• Implement POST /compact route
• Run PostgreSQL VACUUM/optimization
• Run Qdrant collection optimization if available
• Return before/after size metrics
• Add unit tests
• Add integration tests
• Update OpenAPI documentation

API Response

{
  "before_size_mb": 125.4,
  "after_size_mb": 98.2,
  "duration_ms": 3500
}

Related

• See api/codetriever-openapi.yaml for full spec
• Similar to SQL Server index rebuild or PostgreSQL VACUUM