feat: Add database migrations and auth system

- Add Alembic for database migrations
- Implement user authentication system
- Update frontend styles and components
- Add new test audio functionality
- Update stream management and UI

alembic/env.py

@@ -0,0 +1,61 @@
+from logging.config import fileConfig
+import os
+import sys
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+
+# Add the project root to the Python path
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+# Import your SQLAlchemy models and engine
+from models import SQLModel
+from database import engine
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# Import all your SQLModel models here so that Alembic can detect them
+from models import User, DBSession
+
+# Set the target metadata to SQLModel.metadata
+target_metadata = SQLModel.metadata
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode."""
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        compare_type=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+def run_migrations_online() -> None:
+    """Run migrations in 'online' mode."""
+    connectable = engine
+    
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection, 
+            target_metadata=target_metadata,
+            compare_type=True,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()