refactor: split monolithic main.py into services/ + ui/ modules (improve-maintainability)

- main.py: 4360 → 146 lines (96.6% reduction), entry layer only
- services/: rate_limiter, autostart, persona, connection, profile,
  hotspot, content, engagement, scheduler, queue_ops (10 business modules)
- ui/app.py: all Gradio UI code extracted into build_app(cfg, analytics)
- Fix: with gr.Blocks() indented inside build_app function
- Fix: cfg.all property (not get_all method)
- Fix: STATUS_LABELS, get_persona_keywords, fetch_proactive_notes imports
- Fix: queue_ops module-level set_publish_callback moved into configure()
- Fix: pub_queue.format_*() wrapped as queue_format_table/calendar helpers
- All 14 files syntax-verified, build_app() runtime-verified
- 58/58 tasks complete"

openspec/changes/improve-maintainability/specs/services-autostart/spec.md

@@ -0,0 +1,16 @@
+## ADDED Requirements
+
+### Requirement: 开机自启管理函数迁移至独立模块
+系统 SHALL 将开机自启相关常量和函数从 `main.py` 提取至 `services/autostart.py`，包括：`_APP_NAME`、`_STARTUP_REG_KEY`、`_get_startup_script_path`、`_get_startup_bat_path`、`_create_startup_scripts`、`is_autostart_enabled`、`enable_autostart`、`disable_autostart`、`toggle_autostart`。
+
+#### Scenario: 模块导入成功
+- **WHEN** `main.py` 执行 `from services.autostart import toggle_autostart, is_autostart_enabled`
+- **THEN** 函数可正常调用
+
+#### Scenario: Windows 注册表操作行为不变
+- **WHEN** `enable_autostart()` 在 Windows 系统上被调用
+- **THEN** SHALL 向注册表 `HKCU\Software\Microsoft\Windows\CurrentVersion\Run` 写入启动项，行为与迁移前完全一致
+
+#### Scenario: 非 Windows 平台处理不变
+- **WHEN** `enable_autostart()` 在非 Windows 系统上被调用
+- **THEN** SHALL 返回与迁移前相同的平台不支持提示信息