fix: pipeline content tracking + topic article preview

db_helper.py: save_article now calculates and persists word_count
generator.py: run_creator_blocking sets word_count for HTML-imported articles
writer.py: fix title regex stripping content-leading numbers (35岁后→岁后)
trends.py: fix Baidu hot_score str/int type comparison crash
database.py: add missing content_tasks.org_id ALTER TABLE migration
schemas.py + topics.py: topic list API returns article_count + articles[] previews
topics.html: table view and card view show article badges with word counts, clickable to open preview

Ultraworked with Sisyphus

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

platform/backend/app/database.py

@@ -131,6 +131,7 @@ def init_db():
                 ("search_rankings", "org_id", "VARCHAR DEFAULT 'default'"),
                 ("geo_readiness_scores", "org_id", "VARCHAR DEFAULT 'default'"),
                 ("articles", "org_id", "VARCHAR DEFAULT 'default'"),
+                ("content_tasks", "org_id", "VARCHAR DEFAULT 'default'"),
                 ("topics", "series", "VARCHAR"),
             ]:
                 try: