Feature Request: Add DELETE endpoints for Actions and Crystals

Problem

Currently, the agentmemory REST API only provides a DELETE endpoint for Memories (/agentmemory/governance/memories), but not for Actions and Crystals.

Users have no way to delete test/incorrect Actions and Crystals via API.

Proposed Solution

Add REST DELETE endpoints for Actions and Crystals:

1. Actions DELETE endpoint

• Path: DELETE /agentmemory/actions/{actionId}
• Or: DELETE /agentmemory/governance/actions with {"actionIds": ["act_xxx"]}

2. Crystals DELETE endpoint

• Path: DELETE /agentmemory/crystals/{crystalId}
• Or: DELETE /agentmemory/governance/crystals with {"crystalIds": ["crys_xxx"]}

Use Case

• Clean up test data created during development
• Remove incorrect or obsolete records
• Data governance and compliance

Environment

• OS: Windows
• Version: 0.9.12
• Backend: iii-engine (no Docker)