Users, file manager, image generation, budgets and agent workflow

- User management: local accounts (Argon2) and OpenID Connect, admin/user
  roles, per-user folders plus admin-shared folders, read-only session
  sharing, event filtering per user
- File manager with CodeMirror editor and git client (status, diff,
  stage, commit, branches, fetch/pull/push, log, clone/init)
- Image generation via fal.ai: generate_image tool and image page
- Budgets: monthly limits per provider, provider balances/costs
  (OpenRouter, Anthropic admin cost report, fal.ai), price discovery
- Subagents on other models, background tasks, concurrency limits per
  host/model/subagent
- MCP tools loaded on demand (mcp_search/mcp_call), read-only hints
- Permission mode "auto", safe read-only commands always allowed
- Persistent message queue with attachments, deletable
- Live reasoning incl. <think> tags, activity animations, CSS themes,
  mobile layout, statistics per user, upload size handling
- Docker: named volume for state, localhost-bound port

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitignore

@@ -7,3 +7,4 @@
 *.db
 *.db-wal
 *.db-shm
+docker-compose.override.yml