feat: implement GraphQL member management API

Implement complete member management system with GraphQL API per OpenSpec proposal.
Only firstName is required; all other fields are optional with conditional validation.

Key features:
- GraphQL CRUD operations (create, read, update, delete members)
- SQLAlchemy 2.0 async with SQLite database
- Alembic database migrations
- Conditional validation (email/phone validated only when provided)
- Member fields: firstName (required), lastName, address, email, phone (all optional)
- Database seed script with sample member
- FastAPI with Strawberry GraphQL integration

Implementation details:
- Python 3.11+ with uv package manager
- Async database sessions throughout
- Proper error handling and validation
- Code quality: black, isort, ruff
- Comprehensive end-to-end testing completed

All 20 tasks from OpenSpec proposal completed successfully.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

migrations/env.py

@@ -0,0 +1,91 @@
+import asyncio
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import pool
+from sqlalchemy.engine import Connection
+from sqlalchemy.ext.asyncio import async_engine_from_config
+
+# Import config to get database URL
+from src.config import settings
+
+# Import our Base and models
+from src.database import Base
+from src.models import member  # noqa: F401 - import to register models
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Set the database URL from our settings
+config.set_main_option("sqlalchemy.url", settings.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 our Base metadata 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 do_run_migrations(connection: Connection) -> None:
+    """Helper function to run migrations with a connection."""
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations() -> None:
+    """Run migrations in 'online' mode with async support."""
+    connectable = async_engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+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.
+
+    """
+    asyncio.run(run_async_migrations())
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()