chat: run /chat sessions from the dedicated claude_sessions cwd

The standalone /chat route now tags its context as 'chat'; the backend runs those
sessions with cwd = DATA_PATH/<email>/claude_sessions (created on demand), so their
transcripts form an isolated Claude project group instead of polluting the home-dir
history. Other chat contexts (email/project panels) keep their own cwd.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/servers/api/chat/claude-sessions.ts

@@ -1,4 +1,4 @@
-import { readdirSync, readFileSync, existsSync, statSync } from 'node:fs';
+import { readdirSync, readFileSync, existsSync, statSync, mkdirSync } from 'node:fs';
 import { join } from 'node:path';
 import { DATA_PATH } from '../../data-path';
 
@@ -12,6 +12,13 @@ import { DATA_PATH } from '../../data-path';
 /** Dedicated working directory for /chat sessions, so they form their own Claude "project" group. */
 export const getClaudeSessionsCwd = (email: string): string => join(DATA_PATH, email, 'claude_sessions');
 
+/** Same, but create the directory if it doesn't exist (call before spawning a /chat session). */
+export const ensureClaudeSessionsCwd = (email: string): string => {
+  const dir = getClaudeSessionsCwd(email);
+  mkdirSync(dir, { recursive: true });
+  return dir;
+};
+
 const claudeProjectsDir = (email: string): string => join(DATA_PATH, email, 'home', '.claude', 'projects');
 
 /** Claude's folder name for a working directory. */

src/servers/api/pi/websocket.ts

@@ -4,6 +4,7 @@ import type { ClientMessage, ServerMessage, Message, PiEvent } from './types';
 import { sessionManager } from './session-manager';
 import * as storage from './storage';
 import { sendClaudeCodeStreaming } from '@@/channels/send-claude-code';
+import { ensureClaudeSessionsCwd } from '../chat/claude-sessions';
 import * as sidecar from '@@/sidecar-registry';
 import { join } from 'path';
 import { getHomeDirForRole } from '../../../servers/data-path';
@@ -296,7 +297,10 @@ async function handleClaudeCodeChat(
   const { email, username, userId } = ws.data;
   const homeDir = getHomeDirForRole(email, ws.data.role);
 
-  const cwd = resolveCwd(email, ws.data.role, msg.cwd);
+  // The standalone /chat route runs every session from a dedicated `claude_sessions` working
+  // directory, so its transcripts form their own Claude "project" group (source of truth) instead of
+  // polluting the home-dir history. Other contexts (email/project panels) keep their own cwd.
+  const cwd = msg.context === 'chat' ? ensureClaudeSessionsCwd(email) : resolveCwd(email, ws.data.role, msg.cwd);
 
   const groupSlug = msg.groupSlug || null;