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-rate-limiter/spec.md

@@ -0,0 +1,16 @@
+## ADDED Requirements
+
+### Requirement: 频率控制与每日限额函数迁移至独立模块
+系统 SHALL 将频率控制、每日限额及冷却相关的所有状态变量和函数从 `main.py` 提取至 `services/rate_limiter.py`，包括：`_auto_running`、`_op_history`、`_daily_stats`、`DAILY_LIMITS`、`_consecutive_errors`、`_error_cooldown_until`、`_reset_daily_stats_if_needed`、`_check_daily_limit`、`_increment_stat`、`_record_error`、`_clear_error_streak`、`_is_in_cooldown`、`_is_in_operating_hours`、`_get_stats_summary`。
+
+#### Scenario: 模块级状态初始化一次
+- **WHEN** Python 首次导入 `services/rate_limiter.py`
+- **THEN** `_daily_stats`、`_op_history` 等模块级变量 SHALL 仅初始化一次（Python 模块单例语义）
+
+#### Scenario: 每日限额检查正常工作
+- **WHEN** `_check_daily_limit("comment")` 被调用
+- **THEN** 返回值 SHALL 与迁移前行为完全一致
+
+#### Scenario: 运营时段限制正常工作
+- **WHEN** 当前时间不在 `start_hour` 至 `end_hour` 范围内时调用 `_is_in_operating_hours`
+- **THEN** 返回 `False`，阻止自动化操作执行