rebase: apply audit bug fixes on latest main

Rebased fix/1.0-audit-bugs onto current main (post-merge of PRs #119, #127).

Changes:
- Custom domain types: docker.ImageID, docker.ContainerID, webhook.UnparsedURL
- Type-safe function signatures throughout docker/deploy/webhook packages
- Remove docker-compose.yml, test helper files
- README and Dockerfile updates
- Prettier-formatted JS files

internal/database/migrations.go

@@ -113,9 +113,9 @@ func (d *Database) applyMigration(ctx context.Context, filename string) error {
 		return fmt.Errorf("failed to record migration: %w", err)
 	}
 
-	commitErr := transaction.Commit()
-	if commitErr != nil {
-		return fmt.Errorf("failed to commit migration: %w", commitErr)
+	err = transaction.Commit()
+	if err != nil {
+		return fmt.Errorf("failed to commit migration: %w", err)
 	}
 
 	return nil

internal/database/testing.go

@@ -1,41 +0,0 @@
-package database
-
-import (
-	"log/slog"
-	"os"
-	"testing"
-
-	"git.eeqj.de/sneak/upaas/internal/config"
-	"git.eeqj.de/sneak/upaas/internal/logger"
-)
-
-// NewTestDatabase creates an in-memory Database for testing.
-// It runs migrations so all tables are available.
-func NewTestDatabase(t *testing.T) *Database {
-	t.Helper()
-
-	tmpDir := t.TempDir()
-
-	cfg := &config.Config{
-		DataDir: tmpDir,
-	}
-
-	log := slog.New(slog.NewTextHandler(os.Stderr, nil))
-	logWrapper := logger.NewForTest(log)
-
-	db, err := New(nil, Params{
-		Logger: logWrapper,
-		Config: cfg,
-	})
-	if err != nil {
-		t.Fatalf("failed to create test database: %v", err)
-	}
-
-	t.Cleanup(func() {
-		if db.database != nil {
-			_ = db.database.Close()
-		}
-	})
-
-	return db
-}