fix: post new review first, then supersede old with link

Changes the order of operations:
1. POST new review (gets non-stale badge immediately)
2. PATCH old review with superseded message linking to the new one

This gives the superseded comment a clickable link to the current
review, making navigation between review iterations easy.

buildSupersededBody now accepts a newReviewURL parameter.

cmd/review-bot/main.go

@@ -316,29 +316,26 @@ func main() {
 	}
 
 	// --- Review update strategy ---
-	// Always post a fresh review on the current commit. If a previous review
-	// exists, mark it as superseded (preserves old threads as navigable history).
-	// Never skip posting — the fresh review must land on HEAD to clear stale badges.
+	// 1. POST new review first (gets non-stale approval badge on HEAD)
+	// 2. Then supersede old review with link to the new one
+	// Order matters: post first so we have the new review's URL for the supersede message.
+	var existingReview *gitea.Review
+	var existingCommentID int64
 	if *reviewerName != "" {
 		existingReviews, err := giteaClient.ListReviews(ctx, owner, repoName, prNumber)
 		if err != nil {
 			slog.Warn("could not list existing reviews", "pr", prNumber, "error", err)
 		} else {
-			// In shared-token mode, skip superseding to avoid clobbering sibling reviews.
 			sharedToken := hasSharedToken(existingReviews, sentinel)
 			if !sharedToken {
-				existing := findOwnReview(existingReviews, sentinel)
-				if existing != nil {
-					commentID, err := giteaClient.GetTimelineReviewCommentID(ctx, owner, repoName, prNumber, sentinel)
+				existingReview = findOwnReview(existingReviews, sentinel)
+				if existingReview != nil {
+					cid, err := giteaClient.GetTimelineReviewCommentID(ctx, owner, repoName, prNumber, sentinel)
 					if err != nil {
 						slog.Warn("could not find old review comment ID for supersede", "error", err)
+						existingReview = nil // can't supersede without comment ID
 					} else {
-						supersededBody := buildSupersededBody(existing.Body, existing.CommitID, sentinel)
-						if err := giteaClient.EditComment(ctx, owner, repoName, commentID, supersededBody); err != nil {
-							slog.Warn("could not mark old review as superseded", "comment_id", commentID, "error", err)
-						} else {
-							slog.Info("marked old review as superseded", "old_state", existing.State, "pr", prNumber)
-						}
+						existingCommentID = cid
 					}
 				}
 			} else {
@@ -347,7 +344,7 @@ func main() {
 		}
 	}
 
-	// POST new review (first run, or state transition fallthrough)
+	// POST new review
 	slog.Info("posting review", "event", event, "pr", prNumber)
 	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody, inlineComments)
 	if err != nil {
@@ -356,6 +353,17 @@ func main() {
 	}
 	slog.Info("review posted", "review_id", posted.ID, "user", posted.User.Login, "pr", prNumber)
 
+	// Supersede old review with link to the new one
+	if existingReview != nil && existingCommentID > 0 {
+		newReviewURL := fmt.Sprintf("%s/%s/%s/pulls/%d#pullrequestreview-%d", *giteaURL, owner, repoName, prNumber, posted.ID)
+		supersededBody := buildSupersededBody(existingReview.Body, existingReview.CommitID, newReviewURL, sentinel)
+		if err := giteaClient.EditComment(ctx, owner, repoName, existingCommentID, supersededBody); err != nil {
+			slog.Warn("could not mark old review as superseded", "comment_id", existingCommentID, "error", err)
+		} else {
+			slog.Info("marked old review as superseded", "old_state", existingReview.State, "new_review_id", posted.ID, "pr", prNumber)
+		}
+	}
+
 }
 
 // fetchFileContext fetches the full content of modified files from the PR branch.
@@ -514,14 +522,16 @@ func validateReviewerName(name string) error {
 
 // buildSupersededBody creates the body for a superseded review: struck-through banner
 // with collapsed original content and the commit it was evaluated against.
-func buildSupersededBody(originalBody, commitSHA, sentinel string) string {
+func buildSupersededBody(originalBody, commitSHA, newReviewURL, sentinel string) string {
 	shortSHA := commitSHA
 	if len(shortSHA) > 8 {
 		shortSHA = shortSHA[:8]
 	}
 	var sb strings.Builder
 	sb.WriteString("~~Original review~~\n\n")
-	sb.WriteString("**Superseded** \u2014 see current review for up-to-date findings.\n\n")
+	sb.WriteString("**Superseded** \u2014 [see current review](")
+	sb.WriteString(newReviewURL)
+	sb.WriteString(") for up-to-date findings.\n\n")
 	if shortSHA != "" {
 		sb.WriteString("<details><summary>Previous findings (commit ")
 		sb.WriteString(shortSHA)

cmd/review-bot/main_test.go

@@ -60,17 +60,21 @@ func makeReview(id int64, login, state string, stale bool, body string) gitea.Re
 func TestBuildSupersededBody(t *testing.T) {
 	original := "# Review\n\nLooks good.\n\n<!-- review-bot:sonnet -->"
 	sentinel := "<!-- review-bot:sonnet -->"
+	newURL := "https://gitea.example.com/owner/repo/pulls/1#pullrequestreview-99"
 
-	result := buildSupersededBody(original, "abcdef1234567890", sentinel)
+	result := buildSupersededBody(original, "abcdef1234567890", newURL, sentinel)
 
 	// Should contain the struck-through banner
 	if !strings.Contains(result, "~~Original review~~") {
 		t.Error("missing struck-through banner")
 	}
-	// Should contain superseded notice
+	// Should contain superseded notice with link
 	if !strings.Contains(result, "**Superseded**") {
 		t.Error("missing superseded notice")
 	}
+	if !strings.Contains(result, "[see current review]("+newURL+")") {
+		t.Error("missing link to new review")
+	}
 	// Should contain collapsed original
 	if !strings.Contains(result, "<details>") {
 		t.Error("missing details/collapse")
@@ -95,7 +99,7 @@ func TestBuildSupersededBody(t *testing.T) {
 
 func TestBuildSupersededBodyShortSHA(t *testing.T) {
 	// Short SHA should pass through without panic
-	result := buildSupersededBody("body", "abc", "<!-- review-bot:x -->")
+	result := buildSupersededBody("body", "abc", "https://example.com/review", "<!-- review-bot:x -->")
 	if !strings.Contains(result, "abc") {
 		t.Error("short SHA not preserved")
 	}