chat session context scoping, fix sandboxed pi config mounts, dedupe zai/opencode providers

- Add context/contextId fields to session types, storage, and index
- Filter sessions by context (project, workspace, or default chat)
- Pass context through websocket, REST API, and frontend hooks
- Mount ~/.pi/agent into sandboxed containers for auth + writable sessions
- Remove PI_CODING_AGENT_DIR override so container pi uses ~/.pi/agent
- Deduplicate zai/opencode models (same service, show as opencode)

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

src/servers/api/terminal/websocket.ts

@@ -6,6 +6,8 @@ import { fileURLToPath } from 'node:url';
 import { getHomeDir, getGlobalSkillsDir, getGlobalToolsDir, getGlobalExtensionsDir, getUserSkillsDir, getUserToolsDir, DATA_PATH, SERVER_CONFIG_DIR, PI_CONFIG_DIR } from '@@/data-path';
 import { getUsers, getServerIntegration, getUserIntegration } from 'officerdb';
 
+const ensureDir = (dir: string) => { if (!existsSync(dir)) mkdirSync(dir, { recursive: true }); return dir; };
+
 type WSData = { userId: number; email: string; username: string; role: string; sandboxed: boolean; sessionId?: string; cwd?: string; cols?: number; rows?: number };
 type ShellInfo = { command: string; args: string[]; name: string };
 type BridgeSession = {
@@ -191,6 +193,8 @@ const startDockerSidecar = async (port: number, homeDir: string, userId: number,
       '-v', `${getUserSkillsDir(email)}:/officer/user/skills:ro`,
       '-v', `${getUserToolsDir(email)}:/officer/user/tools:ro`,
       '-v', `${PI_CONFIG_DIR}:/officer/pi-config:ro`,
+      '-v', `${PI_CONFIG_DIR}:${containerHome}/.pi/agent`,
+      '-v', `${ensureDir(join(DATA_PATH, email, 'pi-sessions'))}:${containerHome}/.pi/agent/sessions`,
       '-v', `${join(DATA_PATH, '.generated')}:/officer/generated:ro`,
       ...googleMounts,
       '-v', `${join(DATA_PATH, email, 'integrations')}:/officer/user/integrations:ro`,