✨ feat: add Droid agent status hook support

[0xbentang]

Add Factory Droid as a fourth agent integration in Mori, on par with Claude Code, Codex CLI, and Pi.

Changes

• New hook script (mori-droid-hook.sh): Maps Droid lifecycle events to tmux pane options (@mori-agent-state / @mori-agent-name)
• AgentHookConfigurator: isDroidHookInstalled(), installDroidHook(), uninstallDroidHook() — reads/writes ~/.factory/settings.json
• Settings UI: Droid toggle in Settings > Agent Hooks
• AppDelegate: Wires detect/install/uninstall on toggle
• Localization: en + zh-Hans strings

How it works

When enabled, Mori registers hook entries in ~/.factory/settings.json for UserPromptSubmit, PreToolUse, Stop, and Notification events. The hook script sets tmux pane options that Mori already polls every 5s, producing the same badges/tab names/notifications as other agents.

Testing

• All existing tests pass (mise run test)
• Release builds succeed for both Mori (app) and mori (CLI)