feat(memory): add lifecycle hooks and vector memory plugin

Add plugin lifecycle hooks infrastructure:
- before_agent_start: inject context before agent loop
- agent_end: analyze conversation after completion
- 13 hook types total (message, tool, session, gateway hooks)

Memory plugin implementation:
- LanceDB vector storage with OpenAI embeddings
- kind: "memory" to integrate with upstream slot system
- Auto-recall: injects <relevant-memories> when context found
- Auto-capture: stores preferences, decisions, entities
- Rule-based capture filtering with 0.95 similarity dedup
- Tools: memory_recall, memory_store, memory_forget
- CLI: clawdbot ltm list|search|stats

Plugin infrastructure:
- api.on() method for hook registration
- Global hook runner singleton for cross-module access
- Priority ordering and error catching

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/gateway/server/__tests__/test-utils.ts

@@ -5,6 +5,7 @@ export const createTestRegistry = (overrides: Partial<PluginRegistry> = {}): Plu
     plugins: [],
     tools: [],
     hooks: [],
+    typedHooks: [],
     channels: [],
     providers: [],
     gatewayHandlers: {},