fix: WYSIWYG editor, content generation, and writing assistant bug fixes

- Fix text selection menu not showing: wire contentRef via inputRef on multiline TextField
- Fix blog title not truncating: add min-w-0 for flex item overflow
- Fix outline generation 500: escape curly braces in f-string prompt template
- Fix content generation 'NoneType not callable': replace SessionLocal() with get_session_for_user(), add db param to MediumBlogGenerator, fix signature mismatch in database_task_manager
- Fix writing assistant suggest 500: add auth + user_id to API endpoint and service, replace sync requests with httpx.AsyncClient
- Fix hallucination detector 404: explicitly include router in main.py and app.py
- Fix missing error_data in task failure responses
- Hide CopilotKit web inspector button
- Remove hardcoded fallback suggestions from SmartTypingAssist
- Fix stale closure refs in SmartTypingAssist handleTypingChange
- Add two-column editor layout, stats bar, section hover menu
- Various subscription, billing, and research module improvements

backend/api/subscription/utils.py

@@ -14,13 +14,21 @@ def format_plan_limits(plan: SubscriptionPlan) -> Dict[str, Any]:
     """
     Format subscription plan limits for API response.
     
+    Includes _zero_means metadata per field to disambiguate:
+      - 'disabled': 0 means the feature is not available (Free tier)
+      - 'unlimited': 0 means unlimited usage (Enterprise tier)
+      - 'limited': >0 means numerical limit applies
+    
     Args:
         plan: SubscriptionPlan model instance
         
     Returns:
-        Dictionary with formatted limits
+        Dictionary with formatted limits and _zero_means metadata
     """
-    return {
+    tier = plan.tier.value if hasattr(plan.tier, 'value') else str(plan.tier)
+    is_enterprise = tier == 'enterprise'
+    
+    limit_fields = {
         "ai_text_generation_calls": getattr(plan, 'ai_text_generation_calls_limit', None) or 0,
         "gemini_calls": plan.gemini_calls_limit,
         "openai_calls": plan.openai_calls_limit,
@@ -35,11 +43,43 @@ def format_plan_limits(plan: SubscriptionPlan) -> Dict[str, Any]:
         "image_edit_calls": getattr(plan, 'image_edit_calls_limit', 0) or 0,
         "audio_calls": getattr(plan, 'audio_calls_limit', 0) or 0,
         "exa_calls": getattr(plan, 'exa_calls_limit', 0) or 0,
+        "wavespeed_calls": getattr(plan, 'wavespeed_calls_limit', 0) or 0,
         "gemini_tokens": plan.gemini_tokens_limit,
         "openai_tokens": plan.openai_tokens_limit,
         "anthropic_tokens": plan.anthropic_tokens_limit,
         "mistral_tokens": plan.mistral_tokens_limit,
-        "monthly_cost": plan.monthly_cost_limit
+        "monthly_cost": plan.monthly_cost_limit,
+    }
+    
+    # Build _zero_means metadata: indicates whether 0 means 'disabled' or 'unlimited'
+    zero_means = {}
+    for field, value in limit_fields.items():
+        if field == "monthly_cost":
+            zero_means[field] = "disabled"
+        elif is_enterprise:
+            # Enterprise: 0 means unlimited for all call/token fields
+            zero_means[field] = "unlimited"
+        else:
+            # Free/Basic/Pro: determine per-field
+            # Fields that are 0=disabled on Free tier but 0=unlimited on Basic/Pro
+            call_and_token_fields = {
+                "gemini_calls", "openai_calls", "anthropic_calls", "mistral_calls",
+                "tavily_calls", "serper_calls", "metaphor_calls", "firecrawl_calls",
+                "stability_calls", "video_calls", "image_edit_calls", "audio_calls",
+                "exa_calls", "wavespeed_calls", "ai_text_generation_calls",
+                "gemini_tokens", "openai_tokens", "anthropic_tokens", "mistral_tokens",
+            }
+            if field in call_and_token_fields:
+                if value == 0:
+                    zero_means[field] = "disabled" if tier == "free" else "unlimited"
+                else:
+                    zero_means[field] = "limited"
+            else:
+                zero_means[field] = "limited" if value > 0 else "disabled"
+    
+    return {
+        **limit_fields,
+        "_zero_means": zero_means,
     }