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/session/session-manager.ts

@@ -12,7 +12,7 @@ export type SessionManagerOptions = {
 
 export class SessionManager {
   private readonly sessionId: string;
-  private readonly baseDir?: string;
+  private readonly baseDir: string | undefined;
   private readonly maxMessages: number;
   private readonly keepLast: number;
   private queue: Promise<void> = Promise.resolve();

src/agent/session/storage.ts

@@ -5,7 +5,7 @@ import { appendFile, writeFile } from "fs/promises";
 import type { SessionEntry } from "./types.js";
 
 export type SessionStorageOptions = {
-  baseDir?: string;
+  baseDir?: string | undefined;
 };
 
 export function resolveBaseDir(options?: SessionStorageOptions) {