feat: enhanced hook event system for full CC lifecycle

[OneStepAt4time]

Problem

Aegis only receives PreToolUse and PermissionRequest from CC. Many useful orchestration events are lost.

Solution

Add support for all CC lifecycle hooks:

• SessionStart — session initialization
• UserPromptSubmit — user input (keyword detection)
• PostToolUse — after tool calls (verification + memory capture)
• SubagentStart/Stop — sub-agent tracking
• PreCompact — context preservation before compression
• Stop — session termination
• SessionEnd — cleanup

Implementation

• Extend src/hooks.ts for all events
• Each event → SSE broadcast + session state save
• PostToolUse: capture results for memory extraction
• PreCompact: save important state before CC compresses context
• HTTP: GET /v1/hooks/events for available events list

Acceptance Criteria

• All CC lifecycle hooks received and processed
• Events forwarded via SSE to subscribers
• PostToolUse captures results for memory
• PreCompact preserves state

Reference

• OMC: hooks/hooks.json — 13 lifecycle hook points
• CC: src/hooks/ — hook registration pattern

[OneStepAt4time]

✅ PR #964 open. 6 additional CC hook events registered (Worktree*, Elicitation*). CI green. Ready for review.

[OneStepAt4time]

Resolved by PR #964 (merged on 2026-04-03).