fix: Resolve APIProvider enum mismatch causing dashboard errors

- Fix import path in subscriptions.py (pricing_service location)
- Add values_callable to APIUsageLog.provider enum column
- Normalize provider values to lowercase in usage trends helpers
- Add migration script for existing databases

backend/scripts/migrate_api_provider_enum.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+"""
+Migration script to normalize APIProvider enum values to lowercase.
+
+This fixes the issue where the database has uppercase values like "VIDEO", "MISTRAL"
+but the enum expects lowercase values like "video", "mistral".
+
+Run this script once to migrate existing data.
+"""
+
+import os
+import sys
+from pathlib import Path
+
+# Add backend to path
+backend_dir = Path(__file__).parent
+sys.path.insert(0, str(backend_dir))
+
+# Load env first
+from dotenv import load_dotenv
+load_dotenv(backend_dir / '.env')
+
+from loguru import logger
+import sqlite3
+from glob import glob
+
+# Provider mapping: uppercase -> lowercase
+PROVIDER_MAP = {
+    'GEMINI': 'gemini',
+    'OPENAI': 'openai',
+    'ANTHROPIC': 'anthropic',
+    'MISTRAL': 'mistral',
+    'WAVESPEED': 'wavespeed',
+    'TAVILY': 'tavily',
+    'SERPER': 'serper',
+    'METAPHOR': 'metaphor',
+    'FIRECRAWL': 'firecrawl',
+    'STABILITY': 'stability',
+    'EXA': 'exa',
+    'VIDEO': 'video',
+    'IMAGE_EDIT': 'image_edit',
+    'AUDIO': 'audio',
+}
+
+def normalize_provider_value(value: str) -> str:
+    """Convert provider value to lowercase if it's uppercase."""
+    if not value:
+        return value
+    upper_value = value.upper()
+    if upper_value in PROVIDER_MAP:
+        return PROVIDER_MAP[upper_value]
+    # If already lowercase, return as-is
+    return value
+
+def migrate_database(db_path: str) -> tuple[int, int]:
+    """Migrate a single database file. Returns (total_rows, updated_rows)."""
+    try:
+        conn = sqlite3.connect(db_path)
+        cursor = conn.cursor()
+        
+        # Check if api_usage_logs table exists
+        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='api_usage_logs'")
+        if not cursor.fetchone():
+            conn.close()
+            return 0, 0
+        
+        # Get all unique provider values
+        cursor.execute("SELECT DISTINCT provider FROM api_usage_logs")
+        unique_providers = [row[0] for row in cursor.fetchall()]
+        
+        total_rows = 0
+        updated_rows = 0
+        
+        # Count total rows
+        cursor.execute("SELECT COUNT(*) FROM api_usage_logs")
+        total_rows = cursor.fetchone()[0]
+        
+        # Update each provider value that needs normalization
+        for provider in unique_providers:
+            normalized = normalize_provider_value(provider)
+            if provider != normalized:
+                cursor.execute(
+                    "UPDATE api_usage_logs SET provider = ? WHERE provider = ?",
+                    (normalized, provider)
+                )
+                count = cursor.rowcount
+                updated_rows += count
+                logger.info(f"  {db_path}: Updated {count} rows with provider '{provider}' -> '{normalized}'")
+        
+        conn.commit()
+        conn.close()
+        
+        return total_rows, updated_rows
+        
+    except Exception as e:
+        logger.error(f"Error migrating {db_path}: {e}")
+        return 0, 0
+
+def main():
+    """Main migration function."""
+    logger.info("=" * 60)
+    logger.info("APIProvider Enum Normalization Migration")
+    logger.info("=" * 60)
+    
+    # Workspace directory where user databases are stored
+    workspace_dir = backend_dir / "workspace"
+    
+    # Find all database files in workspaces
+    all_dbs = set()
+    
+    if workspace_dir.exists():
+        for workspace in workspace_dir.iterdir():
+            if workspace.is_dir():
+                # Look for database files in workspace subdirectories (database/, or root)
+                for db_pattern in ["**/*.db", "**/alwrity*.db"]:
+                    all_dbs.update(workspace.glob(db_pattern))
+    
+    logger.info(f"Found {len(all_dbs)} database files to check")
+    
+    total_dbs = 0
+    total_rows = 0
+    total_updated = 0
+    
+    for db_path in sorted(all_dbs):
+        total_dbs += 1
+        rows, updated = migrate_database(str(db_path))
+        total_rows += rows
+        total_updated += updated
+    
+    logger.info("=" * 60)
+    logger.info(f"Migration complete!")
+    logger.info(f"  Databases checked: {total_dbs}")
+    logger.info(f"  Total rows: {total_rows}")
+    logger.info(f"  Rows updated: {total_updated}")
+    logger.info("=" * 60)
+    
+    if total_updated > 0:
+        logger.warning("Please restart the backend server to ensure changes take effect.")
+    else:
+        logger.info("No updates needed - all provider values are already normalized.")
+
+if __name__ == "__main__":
+    main()