feat(migrations): T11 setup Alembic and initial schema migration

- Initialize Alembic with alembic init alembic
- Configure alembic.ini to use DATABASE_URL from environment
- Configure alembic/env.py to import Base and models metadata
- Generate initial migration: c92fc544a483_initial_schema
- Migration creates all 4 tables: users, api_keys, api_tokens, usage_stats
- Migration includes all indexes, constraints, and foreign keys
- Test upgrade/downgrade cycle works correctly

Alembic commands:
- alembic upgrade head
- alembic downgrade -1
- alembic revision --autogenerate -m 'message'

Tests: 13 migration tests pass

alembic.ini

@@ -0,0 +1,150 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts.
+# this is typically a path given in POSIX (e.g. forward slashes)
+# format, relative to the token %(here)s which refers to the location of this
+# ini file
+script_location = %(here)s/alembic
+
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
+# Or organize into date-based subdirectories (requires recursive_version_locations = true)
+# file_template = %%(year)d/%%(month).2d/%%(day).2d_%%(hour).2d%%(minute).2d_%%(second).2d_%%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.  for multiple paths, the path separator
+# is defined by "path_separator" below.
+prepend_sys_path = .
+
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the tzdata library which can be installed by adding
+# `alembic[tz]` to the pip requirements.
+# string value is passed to ZoneInfo()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; This defaults
+# to <script_location>/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "path_separator"
+# below.
+# version_locations = %(here)s/bar:%(here)s/bat:%(here)s/alembic/versions
+
+# path_separator; This indicates what character is used to split lists of file
+# paths, including version_locations and prepend_sys_path within configparser
+# files such as alembic.ini.
+# The default rendered in new alembic.ini files is "os", which uses os.pathsep
+# to provide os-dependent path splitting.
+#
+# Note that in order to support legacy alembic.ini files, this default does NOT
+# take place if path_separator is not present in alembic.ini.  If this
+# option is omitted entirely, fallback logic is as follows:
+#
+# 1. Parsing of the version_locations option falls back to using the legacy
+#    "version_path_separator" key, which if absent then falls back to the legacy
+#    behavior of splitting on spaces and/or commas.
+# 2. Parsing of the prepend_sys_path option falls back to the legacy
+#    behavior of splitting on spaces, commas, or colons.
+#
+# Valid values for path_separator are:
+#
+# path_separator = :
+# path_separator = ;
+# path_separator = space
+# path_separator = newline
+#
+# Use os.pathsep. Default configuration used for new projects.
+path_separator = os
+
+# set to 'true' to search source files recursively
+# in each "version_locations" directory
+# new in Alembic version 1.10
+# recursive_version_locations = false
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# database URL.  This is consumed by the user-maintained env.py script only.
+# other means of configuring database URLs may be customized within the env.py
+# file.
+# Use environment variable DATABASE_URL from .env file
+sqlalchemy.url = %(DATABASE_URL)s
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# lint with attempts to fix using "ruff" - use the module runner, against the "ruff" module
+# hooks = ruff
+# ruff.type = module
+# ruff.module = ruff
+# ruff.options = check --fix REVISION_SCRIPT_FILENAME
+
+# Alternatively, use the exec runner to execute a binary found on your PATH
+# hooks = ruff
+# ruff.type = exec
+# ruff.executable = ruff
+# ruff.options = check --fix REVISION_SCRIPT_FILENAME
+
+# Logging configuration.  This is also consumed by the user-maintained
+# env.py script only.
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARNING
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARNING
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

alembic/README

@@ -0,0 +1 @@
+Generic single-database configuration.

alembic/env.py

@@ -0,0 +1,101 @@
+"""Alembic environment configuration.
+
+T11: Setup Alembic and initial schema migration
+"""
+import os
+import sys
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config, pool
+
+from alembic import context
+
+# Add src to path to import models
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+# Import models to register them with Base
+from openrouter_monitor.database import Base
+from openrouter_monitor.models import User, ApiKey, UsageStats, ApiToken
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Override sqlalchemy.url with environment variable if available
+# This allows DATABASE_URL from .env to be used
+database_url = os.getenv('DATABASE_URL')
+if database_url:
+    config.set_main_option('sqlalchemy.url', database_url)
+
+# 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)
+
+# Set target_metadata to the Base.metadata from our models
+# This is required for 'autogenerate' support
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    # For SQLite, we need to handle check_same_thread=False
+    db_url = config.get_main_option("sqlalchemy.url")
+    
+    if db_url and 'sqlite' in db_url:
+        # SQLite specific configuration
+        from sqlalchemy import create_engine
+        connectable = create_engine(
+            db_url,
+            connect_args={"check_same_thread": False},
+            poolclass=pool.NullPool,
+        )
+    else:
+        connectable = engine_from_config(
+            config.get_section(config.config_ini_section, {}),
+            prefix="sqlalchemy.",
+            poolclass=pool.NullPool,
+        )
+
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection, target_metadata=target_metadata
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,28 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, Sequence[str], None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    ${downgrades if downgrades else "pass"}

export/progress.md

@@ -44,13 +44,13 @@
 - [x] T04: Setup file configurazione (.env, config.py) (2024-04-07)
 - [x] T05: Configurare pytest e struttura test (2024-04-07)
 
-### 🗄️ Database & Models (T06-T11) - 5/6 completati
+### 🗄️ Database & Models (T06-T11) - 6/6 completati
 - [x] T06: Creare database.py (connection & session) - ✅ Completato (2026-04-07 11:00)
 - [x] T07: Creare model User (SQLAlchemy) - ✅ Completato (2026-04-07 11:15)
 - [x] T08: Creare model ApiKey (SQLAlchemy) - ✅ Completato (2026-04-07 11:15)
 - [x] T09: Creare model UsageStats (SQLAlchemy) - ✅ Completato (2026-04-07 11:15)
 - [x] T10: Creare model ApiToken (SQLAlchemy) - ✅ Completato (2026-04-07 11:15)
-- [ ] T11: Setup Alembic e creare migrazione iniziale - 🟡 In progress
+- [x] T11: Setup Alembic e creare migrazione iniziale - ✅ Completato (2026-04-07 11:20)
 
 ### 🔐 Servizi di Sicurezza (T12-T16) - 0/5 completati
 - [ ] T12: Implementare EncryptionService (AES-256)

tests/unit/models/test_migrations.py

@@ -0,0 +1,321 @@
+"""Tests for Alembic migrations (T11).
+
+T11: Setup Alembic e migrazione iniziale
+"""
+import pytest
+import os
+import tempfile
+from pathlib import Path
+
+
+@pytest.mark.unit
+class TestAlembicInitialization:
+    """Test Alembic initialization and configuration."""
+    
+    def test_alembic_ini_exists(self):
+        """Test that alembic.ini file exists."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        alembic_ini_path = project_root / "alembic.ini"
+        
+        # Assert
+        assert alembic_ini_path.exists(), "alembic.ini should exist"
+    
+    def test_alembic_directory_exists(self):
+        """Test that alembic directory exists."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        alembic_dir = project_root / "alembic"
+        
+        # Assert
+        assert alembic_dir.exists(), "alembic directory should exist"
+        assert alembic_dir.is_dir(), "alembic should be a directory"
+    
+    def test_alembic_env_py_exists(self):
+        """Test that alembic/env.py file exists."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        env_py_path = project_root / "alembic" / "env.py"
+        
+        # Assert
+        assert env_py_path.exists(), "alembic/env.py should exist"
+    
+    def test_alembic_versions_directory_exists(self):
+        """Test that alembic/versions directory exists."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        versions_dir = project_root / "alembic" / "versions"
+        
+        # Assert
+        assert versions_dir.exists(), "alembic/versions directory should exist"
+    
+    def test_alembic_ini_contains_database_url(self):
+        """Test that alembic.ini contains DATABASE_URL configuration."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        alembic_ini_path = project_root / "alembic.ini"
+        
+        # Act
+        with open(alembic_ini_path, 'r') as f:
+            content = f.read()
+        
+        # Assert
+        assert "sqlalchemy.url" in content, "alembic.ini should contain sqlalchemy.url"
+    
+    def test_alembic_env_py_imports_base(self):
+        """Test that alembic/env.py imports Base from models."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        env_py_path = project_root / "alembic" / "env.py"
+        
+        # Act
+        with open(env_py_path, 'r') as f:
+            content = f.read()
+        
+        # Assert
+        assert "Base" in content or "target_metadata" in content, \
+            "alembic/env.py should reference Base or target_metadata"
+
+
+@pytest.mark.integration
+class TestAlembicMigrations:
+    """Test Alembic migration functionality."""
+    
+    def test_migration_file_exists(self):
+        """Test that at least one migration file exists."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        versions_dir = project_root / "alembic" / "versions"
+        
+        # Act
+        migration_files = list(versions_dir.glob("*.py"))
+        
+        # Assert
+        assert len(migration_files) > 0, "At least one migration file should exist"
+    
+    def test_migration_contains_create_tables(self):
+        """Test that migration contains table creation commands."""
+        # Arrange
+        project_root = Path(__file__).parent.parent.parent.parent
+        versions_dir = project_root / "alembic" / "versions"
+        
+        # Get the first migration file
+        migration_files = list(versions_dir.glob("*.py"))
+        if not migration_files:
+            pytest.skip("No migration files found")
+        
+        migration_file = migration_files[0]
+        
+        # Act
+        with open(migration_file, 'r') as f:
+            content = f.read()
+        
+        # Assert
+        assert "upgrade" in content, "Migration should contain upgrade function"
+        assert "downgrade" in content, "Migration should contain downgrade function"
+    
+    def test_alembic_upgrade_creates_tables(self, tmp_path):
+        """Test that alembic upgrade creates all required tables."""
+        # Arrange
+        import subprocess
+        import sys
+        
+        # Create a temporary database
+        db_path = tmp_path / "test_alembic.db"
+        
+        # Set up environment with test database
+        env = os.environ.copy()
+        env['DATABASE_URL'] = f"sqlite:///{db_path}"
+        env['SECRET_KEY'] = "test-secret-key-min-32-characters-long"
+        env['ENCRYPTION_KEY'] = "test-32-byte-encryption-key!!"
+        
+        # Change to project root
+        project_root = Path(__file__).parent.parent.parent.parent
+        
+        # Act - Run alembic upgrade
+        result = subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Assert
+        assert result.returncode == 0, f"Alembic upgrade failed: {result.stderr}"
+        
+        # Verify database file exists
+        assert db_path.exists(), "Database file should be created"
+    
+    def test_alembic_downgrade_removes_tables(self, tmp_path):
+        """Test that alembic downgrade removes tables."""
+        # Arrange
+        import subprocess
+        import sys
+        
+        # Create a temporary database
+        db_path = tmp_path / "test_alembic_downgrade.db"
+        
+        # Set up environment with test database
+        env = os.environ.copy()
+        env['DATABASE_URL'] = f"sqlite:///{db_path}"
+        env['SECRET_KEY'] = "test-secret-key-min-32-characters-long"
+        env['ENCRYPTION_KEY'] = "test-32-byte-encryption-key!!"
+        
+        # Change to project root
+        project_root = Path(__file__).parent.parent.parent.parent
+        
+        # Act - First upgrade
+        subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Then downgrade
+        result = subprocess.run(
+            [sys.executable, "-m", "alembic", "downgrade", "-1"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Assert
+        assert result.returncode == 0, f"Alembic downgrade failed: {result.stderr}"
+    
+    def test_alembic_upgrade_downgrade_cycle(self, tmp_path):
+        """Test that upgrade followed by downgrade and upgrade again works."""
+        # Arrange
+        import subprocess
+        import sys
+        
+        # Create a temporary database
+        db_path = tmp_path / "test_alembic_cycle.db"
+        
+        # Set up environment with test database
+        env = os.environ.copy()
+        env['DATABASE_URL'] = f"sqlite:///{db_path}"
+        env['SECRET_KEY'] = "test-secret-key-min-32-characters-long"
+        env['ENCRYPTION_KEY'] = "test-32-byte-encryption-key!!"
+        
+        # Change to project root
+        project_root = Path(__file__).parent.parent.parent.parent
+        
+        # Act - Upgrade
+        result1 = subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Downgrade
+        result2 = subprocess.run(
+            [sys.executable, "-m", "alembic", "downgrade", "-1"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Upgrade again
+        result3 = subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Assert
+        assert result1.returncode == 0, "First upgrade failed"
+        assert result2.returncode == 0, "Downgrade failed"
+        assert result3.returncode == 0, "Second upgrade failed"
+
+
+@pytest.mark.integration
+class TestDatabaseTables:
+    """Test that database tables are created correctly."""
+    
+    def test_users_table_created(self, tmp_path):
+        """Test that users table is created by migration."""
+        # Arrange
+        import subprocess
+        import sys
+        from sqlalchemy import create_engine, inspect
+        
+        # Create a temporary database
+        db_path = tmp_path / "test_tables.db"
+        
+        # Set up environment with test database
+        env = os.environ.copy()
+        env['DATABASE_URL'] = f"sqlite:///{db_path}"
+        env['SECRET_KEY'] = "test-secret-key-min-32-characters-long"
+        env['ENCRYPTION_KEY'] = "test-32-byte-encryption-key!!"
+        
+        # Change to project root
+        project_root = Path(__file__).parent.parent.parent.parent
+        
+        # Act - Run alembic upgrade
+        subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Verify tables
+        engine = create_engine(f"sqlite:///{db_path}")
+        inspector = inspect(engine)
+        tables = inspector.get_table_names()
+        
+        # Assert
+        assert "users" in tables, "users table should be created"
+        assert "api_keys" in tables, "api_keys table should be created"
+        assert "usage_stats" in tables, "usage_stats table should be created"
+        assert "api_tokens" in tables, "api_tokens table should be created"
+        
+        engine.dispose()
+    
+    def test_alembic_version_table_created(self, tmp_path):
+        """Test that alembic_version table is created."""
+        # Arrange
+        import subprocess
+        import sys
+        from sqlalchemy import create_engine, inspect
+        
+        # Create a temporary database
+        db_path = tmp_path / "test_version.db"
+        
+        # Set up environment with test database
+        env = os.environ.copy()
+        env['DATABASE_URL'] = f"sqlite:///{db_path}"
+        env['SECRET_KEY'] = "test-secret-key-min-32-characters-long"
+        env['ENCRYPTION_KEY'] = "test-32-byte-encryption-key!!"
+        
+        # Change to project root
+        project_root = Path(__file__).parent.parent.parent.parent
+        
+        # Act - Run alembic upgrade
+        subprocess.run(
+            [sys.executable, "-m", "alembic", "upgrade", "head"],
+            cwd=project_root,
+            env=env,
+            capture_output=True,
+            text=True
+        )
+        
+        # Verify tables
+        engine = create_engine(f"sqlite:///{db_path}")
+        inspector = inspect(engine)
+        tables = inspector.get_table_names()
+        
+        # Assert
+        assert "alembic_version" in tables, "alembic_version table should be created"
+        
+        engine.dispose()