feat: auto memory pipeline — host-driven Memento recall/reflect

Add automatic memory integration so EJClaw host directly calls Memento
MCP for recall at session start and reflect on compact, removing
reliance on agent voluntary tool use.

Stage 1: New sessions get room memory briefing injected into system
prompt (CLAUDE.md / AGENTS.md) via host-side MCP client.

Stage 2: PreCompact hook automatically calls reflect + remember to
persist session summaries as room-memory fragments.

Also restores missing source files (token-rotation, codex-token-rotation,
claude-usage exports) to fix full build from source.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -20,6 +20,7 @@
     "test:watch": "vitest"
   },
   "dependencies": {
+    "@modelcontextprotocol/sdk": "^1.27.1",
     "better-sqlite3": "^11.8.1",
     "cron-parser": "^5.5.0",
     "discord.js": "^14.18.0",