Migrate from file-based to database-backed stream metadata storage

- Add PublicStream model and migration
- Update list_streams.py and upload.py to use database
- Add import script for data migration
- Remove public_streams.txt (replaced by database)
- Fix quota sync between userquota and publicstream tables

import_streams.py

@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+"""
+Script to import stream data from backup file into the publicstream table.
+"""
+import json
+from datetime import datetime
+from pathlib import Path
+from sqlalchemy import create_engine, select
+from sqlalchemy.orm import sessionmaker
+from sqlmodel import Session
+from models import PublicStream, User, UserQuota, DBSession, UploadLog
+from database import engine
+
+# Database connection URL - using the same as in database.py
+DATABASE_URL = "postgresql://d2s:kuTy4ZKs2VcjgDh6@localhost:5432/dictastream"
+
+def import_streams_from_backup(backup_file: str):
+    """Import stream data from backup file into the database."""
+    # Set up database connection
+    SessionLocal = sessionmaker(bind=engine)
+    
+    with Session(engine) as session:
+        try:
+            # Read the backup file
+            with open(backup_file, 'r') as f:
+                for line in f:
+                    line = line.strip()
+                    if not line:
+                        continue
+                    
+                    try:
+                        # Parse the JSON data
+                        stream_data = json.loads(line)
+                        uid = stream_data.get('uid')
+                        size = stream_data.get('size', 0)
+                        mtime = stream_data.get('mtime', int(datetime.now().timestamp()))
+                        
+                        if not uid:
+                            print(f"Skipping invalid entry (missing uid): {line}")
+                            continue
+                        
+                        # Check if the stream already exists
+                        existing = session.exec(
+                            select(PublicStream).where(PublicStream.uid == uid)
+                        ).first()
+                        
+                        now = datetime.utcnow()
+                        
+                        if existing:
+                            # Update existing record
+                            existing.size = size
+                            existing.mtime = mtime
+                            existing.updated_at = now
+                            session.add(existing)
+                            print(f"Updated stream: {uid}")
+                        else:
+                            # Create new record
+                            stream = PublicStream(
+                                uid=uid,
+                                size=size,
+                                mtime=mtime,
+                                created_at=now,
+                                updated_at=now
+                            )
+                            session.add(stream)
+                            print(f"Added stream: {uid}")
+                        
+                        # Commit after each record to ensure data integrity
+                        session.commit()
+                        
+                    except json.JSONDecodeError as e:
+                        print(f"Error parsing line: {line}")
+                        print(f"Error: {e}")
+                        session.rollback()
+                    except Exception as e:
+                        print(f"Error processing line: {line}")
+                        print(f"Error: {e}")
+                        session.rollback()
+            
+            print("Import completed successfully!")
+            
+        except Exception as e:
+            session.rollback()
+            print(f"Error during import: {e}")
+            raise
+
+if __name__ == "__main__":
+    backup_file = "public_streams.txt.backup"
+    if not Path(backup_file).exists():
+        print(f"Error: Backup file '{backup_file}' not found.")
+        exit(1)
+    
+    print(f"Starting import from {backup_file}...")
+    import_streams_from_backup(backup_file)