feat(podcast): add pre-estimate endpoint, enhance cost estimator with multi-model support, cleanup alpha pricing seeding

- Add POST /podcast/pre-estimate endpoint for cost estimation before analysis
- Enhance cost_estimator.py with multi-model support (gemini, audio, voice clone, image, video)
- Add detailed cost breakdown (llm, audio, media costs + per-phase breakdown)
- Remove redundant pricing seeding from init_alpha_subscription_tiers.py
- Add SSOT pricing via PricingService.initialize_default_pricing()
- Update TopicUrlInput tooltip to show estimate details
- Add debug logging for pricing seeding and pre-estimate
- Clean up verbose podcast mode debug logs in app.py

backend/app.py

@@ -52,7 +52,7 @@ def is_podcast_only_demo_mode() -> bool:
     env_val = os.getenv("ALWRITY_ENABLED_FEATURES", "all")
     enabled = get_enabled_features()
     result = "podcast" in enabled and "all" not in enabled
-    print(f"[DEBUG] is_podcast_only_demo_mode: ALWRITY_ENABLED_FEATURES={env_val}, enabled={enabled}, result={result}", flush=True)
+    # Removed debug print - too verbose during startup
     return result
 
 
@@ -712,6 +712,9 @@ async def startup_event():
     try:
         _log_memory_usage()
         
+        # Note: Pricing is initialized per-user in services/database.py:init_user_database()
+        # which runs on first database access for each user. No global seeding needed at startup.
+        
         # Skip startup health checks in podcast-only mode to avoid unnecessary DB errors
         if not is_podcast_only_demo_mode():
             startup_report = run_startup_health_routine(app)