fix: make boolean fields resilient to NULL values

Problem: Features with NULL values in passes/in_progress fields caused
Pydantic validation errors in the API.

Solution - defense in depth:
1. Database model: Add nullable=False to passes and in_progress columns
2. Migration: Auto-fix existing NULL values to False on database connect
3. API layer: Handle NULL gracefully in feature_to_response (treat as False)
4. MCP server: Explicitly set in_progress=False when creating features

This ensures:
- New databases cannot have NULL boolean fields
- Existing databases are auto-migrated on connect
- Even if NULL values exist, they're handled gracefully at runtime

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/routers/features.py

@@ -72,7 +72,10 @@ def get_db_session(project_dir: Path):
 
 
 def feature_to_response(f) -> FeatureResponse:
-    """Convert a Feature model to a FeatureResponse."""
+    """Convert a Feature model to a FeatureResponse.
+
+    Handles legacy NULL values in boolean fields by treating them as False.
+    """
     return FeatureResponse(
         id=f.id,
         priority=f.priority,
@@ -80,8 +83,9 @@ def feature_to_response(f) -> FeatureResponse:
         name=f.name,
         description=f.description,
         steps=f.steps if isinstance(f.steps, list) else [],
-        passes=f.passes,
-        in_progress=f.in_progress,
+        # Handle legacy NULL values gracefully - treat as False
+        passes=f.passes if f.passes is not None else False,
+        in_progress=f.in_progress if f.in_progress is not None else False,
     )