feat: Implement agent-pd-defensive (reference agent implementation)

[dcplatforms]

Overview

Implement agent-pd-defensive — the Defensive Cybersecurity agent and reference implementation for all subsequent agents. All other agents follow this module's pattern exactly.

Spec: specs/personas/pd-defensive.yaml

Implementation

• AgentPDDefensive class in src/agents/pd_defensive/
• All T3 tools as async methods (siem_query, edr_query, threat_intel_lookup, etc.)
• T2 action proposal only (no execution) for ioc_block_recommend, alert_escalate_to_ir
• Integrate with MemoryManager (working + episodic read/write + semantic read)
• Integrate with Trust Broker for any inter-agent calls
• Integrate with Autonomy Gate for all action proposals
• Write /prompts/pd-defensive/system.md, memory_inject.md, output_schema.json

Note

This is the first agent. Its structure becomes the template for all 40 remaining agents.