email: store emails.db per account under email_accounts/<account>/

Reorganizes email storage: the DB moves from DATA_PATH/<user>/emails.db to
DATA_PATH/<user>/email_accounts/<accountEmail>/emails.db, with a shared
email_accounts/attachment_cache/ (was Gmail/emails/attachments). openEmailDb now
takes (owner, account); a new openUserEmailDb(owner, userId) resolves the user's
configured account (first enabled) for read paths. Threads the account through
email.ts, accounts, resync, queue sync, channel handlers, and the email_db MCP
tool path. Drops the dead getUserEmailDir helper.

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

src/servers/sidecar/claude/user-instance.ts

@@ -8,7 +8,7 @@ import { SANDBOX_DATA } from '../sandbox';
 import * as claudeManager from './claude-manager';
 import { createSidecarConnector } from '../connect';
 import { sign } from '../../jwt';
-import { getUserByEmail } from 'officerdb';
+import { getUserByEmail, getEmailAccounts } from 'officerdb';
 
 const email = process.env.CLAUDE_USER_EMAIL;
 if (!email) {
@@ -38,6 +38,10 @@ const OFFICER_AUTH_TOKEN = await sign(
 const homeDir =
   dbUser.role === 'Super Admin' ? (process.env.HOME_DIR ?? homedir()) : join(DATA_PATH, email, 'home');
 const globalToolsDir = join(DATA_PATH, 'tools');
+
+// The email_db MCP tool reads one account's SQLite store; use the user's first configured account.
+const emailAccounts = await getEmailAccounts(dbUser.id);
+const emailDbRel = join('email_accounts', emailAccounts[0]?.email ?? 'none', 'emails.db');
 const userToolsDir = join(DATA_PATH, email, 'tools');
 
 // ── Path setup ──
@@ -90,7 +94,7 @@ function generateMcpConfig(): McpPaths {
         args: ['run', MCP_SERVER_SCRIPT],
         env: {
           PI_TOOLS_DIRS: sandboxToolsDirs,
-          OFFICER_EMAIL_DB: `${SANDBOX_DATA}/emails.db`,
+          OFFICER_EMAIL_DB: `${SANDBOX_DATA}/${emailDbRel}`,
           MCP_TOOLS_LOG: `${SANDBOX_DATA}/logs/mcp-tools.log`,
           OFFICER_API_URL,
           OFFICER_AUTH_TOKEN,
@@ -110,7 +114,7 @@ function generateMcpConfig(): McpPaths {
         args: ['run', MCP_SERVER_SCRIPT],
         env: {
           PI_TOOLS_DIRS: hostToolsDirs,
-          OFFICER_EMAIL_DB: join(userRoot, 'emails.db'),
+          OFFICER_EMAIL_DB: join(userRoot, emailDbRel),
           MCP_TOOLS_LOG: join(userRoot, 'logs', 'mcp-tools.log'),
           OFFICER_API_URL,
           OFFICER_AUTH_TOKEN,