feat: scaffold work queue API

internal/db/sqlite.go

@@ -0,0 +1,32 @@
+package db
+
+import (
+	"database/sql"
+	_ "embed"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+//go:embed migrations/001_initial.sql
+var initialMigration string
+
+func Open(databaseURL string) (*sql.DB, error) {
+	if err := os.MkdirAll(filepath.Dir(databaseURL), 0o755); err != nil && filepath.Dir(databaseURL) != "." {
+		return nil, fmt.Errorf("mkdir db dir: %w", err)
+	}
+
+	db, err := sql.Open("sqlite3", databaseURL+"?_foreign_keys=on&_busy_timeout=5000")
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := db.Exec(initialMigration); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("apply migration: %w", err)
+	}
+
+	return db, nil
+}