feat(agent): add profile system and improve tools

- Add Agent Profile module for managing agent identity, soul, tools,
  memory, and bootstrap configuration
- Add profile CLI (pnpm agent:profile) for creating/listing/showing profiles
- Default sessionId to UUIDv7 instead of "default"
- Expose Agent.sessionId as public readonly property
- Improve exec/process tools error handling (no more crashes on spawn errors)
- Add 'output' action to process tool for reading stdout/stderr
- Better tool descriptions to guide agent in choosing exec vs process

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

src/agent/index.ts

@@ -1,2 +1,3 @@
 export * from "./runner.js";
 export * from "./types.js";
+export * from "./profile/index.js";