Add auto-migration on database startup

- Embed migrations/001_initial.sql into the binary
- Run migrations automatically when connecting to database
- Uses CREATE TABLE IF NOT EXISTS for idempotent execution

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

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

internal/storage/database.go

@@ -3,6 +3,7 @@ package storage
 import (
 	"context"
 	"database/sql"
+	_ "embed"
 	"fmt"
 	"time"
 
@@ -12,12 +13,15 @@ import (
 	_ "github.com/lib/pq"
 )
 
+//go:embed migrations/001_initial.sql
+var migrationSQL string
+
 // Database handles all database operations
 type Database struct {
 	db *sql.DB
 }
 
-// NewDatabase creates a new database connection
+// NewDatabase creates a new database connection and runs migrations
 func NewDatabase(cfg *config.DatabaseConfig) (*Database, error) {
 	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
 		cfg.Host, cfg.Port, cfg.User, cfg.Password, cfg.DBName, cfg.SSLMode)
@@ -31,7 +35,20 @@ func NewDatabase(cfg *config.DatabaseConfig) (*Database, error) {
 		return nil, fmt.Errorf("failed to ping database: %w", err)
 	}
 
-	return &Database{db: db}, nil
+	d := &Database{db: db}
+
+	// Run migrations
+	if err := d.runMigrations(); err != nil {
+		return nil, fmt.Errorf("failed to run migrations: %w", err)
+	}
+
+	return d, nil
+}
+
+// runMigrations executes the embedded SQL migrations
+func (d *Database) runMigrations() error {
+	_, err := d.db.Exec(migrationSQL)
+	return err
 }
 
 // Close closes the database connection