feat: Add automatic migrations system

- New run_migrations.py script
- Runs all SQL files in migrations/ on startup
- Tracks executed migrations in schema_migrations table
- Retries database connection (30 attempts)
- Separate Shinkan DB (shinkan_dev / shinkan)

This ensures a clean separation from Mitai database.

backend/main.py

@@ -9,7 +9,15 @@ from fastapi.responses import JSONResponse
 import os
 
 from version import APP_VERSION, BUILD_DATE, DB_SCHEMA_VERSION, MODULE_VERSIONS
-from db_init import init_db
+
+# Run database migrations on startup
+try:
+    import run_migrations
+    run_migrations.main()
+    print("✓ Database migrations completed")
+except Exception as e:
+    print(f"⚠ Warning: Migration error: {e}")
+    print("  Continuing startup - migrations may need manual intervention")
 
 # Initialize FastAPI app
 app = FastAPI(
@@ -29,8 +37,7 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-# Initialize Database (runs migrations automatically)
-init_db()
+# TODO: Initialize Database with migrations
 
 # Version Endpoint (public, no auth)
 @app.get("/api/version")

backend/run_migrations.py

@@ -0,0 +1,148 @@
+#!/usr/bin/env python3
+"""
+Shinkan Jinkendo - Database Migrations Runner
+
+Runs all SQL migrations in backend/migrations/ directory
+Tracks executed migrations in schema_migrations table
+"""
+import os
+import sys
+import psycopg2
+from psycopg2 import sql
+import time
+
+def get_db_connection():
+    """Get database connection with retries"""
+    max_retries = 30
+    for i in range(max_retries):
+        try:
+            conn = psycopg2.connect(
+                host=os.getenv("DB_HOST", "localhost"),
+                port=os.getenv("DB_PORT", "5432"),
+                database=os.getenv("DB_NAME", "shinkan_dev"),
+                user=os.getenv("DB_USER", "shinkan_dev"),
+                password=os.getenv("DB_PASSWORD", "dev_password")
+            )
+            print(f"✓ Connected to database: {os.getenv('DB_NAME')}")
+            return conn
+        except psycopg2.OperationalError as e:
+            if i < max_retries - 1:
+                print(f"Waiting for database... ({i+1}/{max_retries})")
+                time.sleep(2)
+            else:
+                print(f"✗ Failed to connect to database after {max_retries} attempts")
+                raise
+
+def init_migrations_table(conn):
+    """Create schema_migrations table if not exists"""
+    with conn.cursor() as cur:
+        cur.execute("""
+            CREATE TABLE IF NOT EXISTS schema_migrations (
+                id SERIAL PRIMARY KEY,
+                migration VARCHAR(255) UNIQUE NOT NULL,
+                executed_at TIMESTAMP DEFAULT NOW()
+            )
+        """)
+        conn.commit()
+    print("✓ Migrations table initialized")
+
+def get_executed_migrations(conn):
+    """Get list of already executed migrations"""
+    with conn.cursor() as cur:
+        cur.execute("SELECT migration FROM schema_migrations ORDER BY migration")
+        return set(row[0] for row in cur.fetchall())
+
+def get_pending_migrations(executed):
+    """Get list of pending migrations from migrations directory"""
+    migrations_dir = "/app/migrations"
+    if not os.path.exists(migrations_dir):
+        migrations_dir = "backend/migrations"  # Local development
+
+    all_migrations = []
+    for filename in sorted(os.listdir(migrations_dir)):
+        if filename.endswith('.sql') and filename[0].isdigit():
+            migration_name = filename.replace('.sql', '')
+            if migration_name not in executed:
+                all_migrations.append((migration_name, os.path.join(migrations_dir, filename)))
+
+    return all_migrations
+
+def run_migration(conn, migration_name, filepath):
+    """Run a single migration file"""
+    print(f"Running migration: {migration_name}")
+
+    with open(filepath, 'r', encoding='utf-8') as f:
+        sql_content = f.read()
+
+    try:
+        with conn.cursor() as cur:
+            # Execute migration
+            cur.execute(sql_content)
+
+            # Record migration
+            cur.execute(
+                "INSERT INTO schema_migrations (migration) VALUES (%s)",
+                (migration_name,)
+            )
+
+        conn.commit()
+        print(f"  ✓ {migration_name} executed successfully")
+        return True
+
+    except Exception as e:
+        conn.rollback()
+        print(f"  ✗ {migration_name} failed: {e}")
+        return False
+
+def main():
+    """Main migrations runner"""
+    print("=" * 60)
+    print("Shinkan Jinkendo - Database Migrations")
+    print("=" * 60)
+
+    try:
+        # Connect to database
+        conn = get_db_connection()
+
+        # Initialize migrations tracking
+        init_migrations_table(conn)
+
+        # Get executed and pending migrations
+        executed = get_executed_migrations(conn)
+        pending = get_pending_migrations(executed)
+
+        if not pending:
+            print("✓ No pending migrations - database is up to date")
+            return 0
+
+        print(f"\nFound {len(pending)} pending migration(s):")
+        for name, _ in pending:
+            print(f"  - {name}")
+        print()
+
+        # Run pending migrations
+        failed = []
+        for migration_name, filepath in pending:
+            if not run_migration(conn, migration_name, filepath):
+                failed.append(migration_name)
+                break  # Stop on first failure
+
+        conn.close()
+
+        # Summary
+        print("\n" + "=" * 60)
+        if failed:
+            print(f"✗ Migration failed: {failed[0]}")
+            print("=" * 60)
+            return 1
+        else:
+            print(f"✓ All migrations executed successfully ({len(pending)} total)")
+            print("=" * 60)
+            return 0
+
+    except Exception as e:
+        print(f"\n✗ Error: {e}")
+        return 1
+
+if __name__ == "__main__":
+    sys.exit(main())