feat: FAQ/HowTo schema injection and SEO pipeline enhancement

- writer.py: inject_geo_metadata now detects content type (article/listicle/howto/faq/review) and injects appropriate JSON-LD (FAQPage, HowTo, ItemList)
- New helpers: _detect_content_type, _extract_faq_pairs, _extract_howto_steps
- outline.py: _extract_seo_keywords regex support for CJK
- prompt_loader.py: Minor update

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

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

platform/backend/app/core/prompt_loader.py

@@ -30,11 +30,10 @@ _SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=_engine)
 
 
 def _get_session():
-    session = _SessionLocal()
     try:
+        session = _SessionLocal()
         return session
-    except:
-        session.close()
+    except Exception:
         raise