chat: rename claude_sessions → general_chat_sessions; drop dead chat_sessions

The default /chat working directory is used by both the Claude and OpenCode harnesses
now, so its Claude-specific name was misleading.

- Rename the dir + accessors: getClaudeSessionsCwd → getGeneralChatSessionsCwd,
  ensureClaudeSessionsCwd → ensureGeneralChatSessionsCwd, path segment claude_sessions
  → general_chat_sessions (data-path on disk + code + UI labels/comments). No history
  migration — the old Claude transcript slug is orphaned (intentionally).

- Remove the vestigial chat_sessions dir (leftover from the retired session store):
  it only ever held empty claude/archived/ dirs, recreated by a signin hook. Drop that
  hook (+ its dead imports) and the 4 unused data-path accessors (getUserSessionsDir,
  getClaudeDir, getSessionDir, getArchivedSessionDir), and delete the dir.

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

src/servers/api/auth/signin.ts

@@ -1,9 +1,6 @@
 import type { Handler } from 'hono';
-import { mkdir } from 'node:fs/promises';
-import { join } from 'node:path';
 import { getUserByEmail, getPasskeysByUserIdAndOrigin } from 'officerdb';
 import { sign } from '@@/jwt';
-import { getClaudeDir } from '@@/data-path';
 import argon2 from 'argon2';
 import * as errors from '@@/custom-errors';
 import { isLockdown, noteBlocked } from './panic';
@@ -33,8 +30,6 @@ export const signinHandler: Handler = async function (ctx) {
 
   const { id, name, username, role } = dbUser;
 
-  mkdir(join(getClaudeDir(email), 'archived'), { recursive: true }).catch(() => {});
-
   const tokenUser = { id, email, name, username, role, passkeys: passkeys.length };
 
   if (passkeys.length > 0 && !origin.startsWith('chrome-extension://') && !TEST_USERS.includes(dbUser.id)) {