fixed issues from opencode agent

internal/domain/scanning/scanner.go

@@ -69,7 +69,10 @@ func (s *Scanner) scanPush(evt events.PushEvent) {
 
 	// Resolve repo.
 	var repo models.Repository
-	if found, _ := s.db.ID(evt.RepoID).Get(&repo); !found {
+	if found, err := s.db.ID(evt.RepoID).Get(&repo); err != nil {
+		log.Printf("scanning: look up repo %d: %v", evt.RepoID, err)
+		return
+	} else if !found {
 		return
 	}
 
@@ -112,11 +115,11 @@ func (s *Scanner) scanPush(evt events.PushEvent) {
 
 // getDiff returns the unified diff of all changes between two refs.
 func (s *Scanner) getDiff(repoPath, oldRef, newRef string) ([]byte, error) {
-	// If oldRef is the zero OID (new branch), just get the initial commit content.
+	// If oldRef is the zero OID (new branch), diff-tree against the empty tree so
+	// we get actual file contents rather than ls-tree metadata.
 	zeroOID := "0000000000000000000000000000000000000000"
 	if oldRef == zeroOID {
-		// Show the entire tree at the new ref.
-		out, err := gitdomain.Run(repoPath, "ls-tree", "-r", newRef)
+		out, err := gitdomain.Run(repoPath, "diff-tree", "--no-commit-id", "-r", "-p", newRef)
 		if err != nil {
 			return nil, err
 		}