feat: Wave 2 - API org isolation + factory.html + insights.html

- Add org_id auto-population to articles.py, publishing.py, metrics.py
- Add org_id filtering to search_rankings.py geo endpoints
- Add org_id to calendar.py create/update/delete endpoints
- Add org_id to tasks.py create endpoints
- Create factory.html content pipeline page (3-tab: 待创作/进行中/待审查)
- Create insights.html analytics page (4-tab: 概览/搜索排名/GEO/平台对比)

platform/backend/app/api/metrics.py

@@ -179,7 +179,7 @@ def create_metric(
         db.refresh(existing)
         return existing
 
-    metric = ContentMetrics(**data.model_dump(), last_fetched=datetime.now())
+    metric = ContentMetrics(**data.model_dump(), last_fetched=datetime.now(), org_id=topic.org_id)
     db.add(metric)
     db.commit()
     db.refresh(metric)
@@ -401,6 +401,7 @@ def fetch_zhihu_metrics(
             metric = ContentMetrics(
                 topic_id=data.topic_id,
                 platform=platform,
+                org_id=topic.org_id,
                 **metric_data,
                 last_fetched=datetime.now()
             )