feat: Phase 4 多租户隔离 + 四阶段升级测试 + CSS 统一化

Phase 4: org_id 注入 JWT/API 过滤/组织管理 CRUD/前端组织列
测试: tests/test_phase_upgrades.py 97项全覆盖
CSS: theme-modern.css 共享 mobile-card-list/status-dot/search-bar 等模式
修复: initial_data.py LLM配置 NOT NULL 约束, TopicResponse 含 org_id

platform/backend/app/main.py

@@ -9,7 +9,7 @@ from pathlib import Path
 
 from .database import engine, get_db, init_db
 from .models import Base
-from .api import topics, system, articles, publishing, auth, admin, audit, optimizer_logs, cases, task_logs, llm_configs, system_configs, topic_config, calendar, metrics, assets, tasks, platform_config
+from .api import topics, system, articles, publishing, auth, admin, audit, optimizer_logs, cases, task_logs, llm_configs, system_configs, topic_config, calendar, metrics, assets, tasks, platform_config, collector_mgmt
 from .initial_data import import_initial_data
 from .core.scheduler import scheduler
 
@@ -67,6 +67,7 @@ app.include_router(metrics.router)
 app.include_router(assets.router)
 app.include_router(tasks.router)
 app.include_router(platform_config.router)
+app.include_router(collector_mgmt.router)
 
 # 挂载前端
 FRONTEND_DIR = Path(__file__).parent.parent.parent / "frontend"