Add two hooks:
- after_tool_call: fire-and-forget observation to claude-mem
(skips memory_* tools to prevent recursion)
- before_agent_start: context injection from memory search
(wraps in <claude-mem-context> tags)
Both hooks have error handling and graceful degradation.
Part of claude-mem integration (Phase 4/7).
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>