Backend:

Fixed the undefined: prWithReviewers compile error — added prResponse struct and prWithReviewers helper in prs.go, and updated Get to return reviewers alongside the PR
Registered PRSettingsHandler in router.go with routes for /default-reviewers, /default-description, and /excluded-files under /{owner}/{repo}
Frontend (prs.ts):

useDefaultReviewers / useAddDefaultReviewer / useRemoveDefaultReviewer
useDefaultDescription / useUpdateDefaultDescription
useExcludedFiles / useUpdateExcludedFiles
RepoSettingsPage.tsx — three new fully functional sections:

Default reviewers — avatar list with add/remove, auto-assigned on PR creation
Default description — Markdown textarea pre-fills new PR bodies
Excluded files — glob patterns textarea, excludes matched files from PR diffs

internal/api/handlers/pr_settings.go

@@ -21,12 +21,22 @@ func (h *PRSettingsHandler) resolveRepo(w http.ResponseWriter, r *http.Request)
 	ownerName := chi.URLParam(r, "owner")
 	repoName := chi.URLParam(r, "repo")
 	var owner models.User
-	if found, _ := h.db.Where("username = ?", ownerName).Get(&owner); !found {
+	found, err := h.db.Where("username = ?", ownerName).Get(&owner)
+	if err != nil {
+		jsonError(w, "database error: "+err.Error(), http.StatusInternalServerError)
+		return nil, false
+	}
+	if !found {
 		jsonError(w, "repository not found", http.StatusNotFound)
 		return nil, false
 	}
 	var repo models.Repository
-	if found, _ := h.db.Where("owner_id = ? AND name = ?", owner.ID, repoName).Get(&repo); !found {
+	found, err = h.db.Where("owner_id = ? AND name = ?", owner.ID, repoName).Get(&repo)
+	if err != nil {
+		jsonError(w, "database error: "+err.Error(), http.StatusInternalServerError)
+		return nil, false
+	}
+	if !found {
 		jsonError(w, "repository not found", http.StatusNotFound)
 		return nil, false
 	}
@@ -92,7 +102,12 @@ func (h *PRSettingsHandler) AddDefaultReviewer(w http.ResponseWriter, r *http.Re
 	}
 
 	var u models.User
-	if found, _ := h.db.Where("username = ?", body.Username).Get(&u); !found {
+	found, err := h.db.Where("username = ?", body.Username).Get(&u)
+	if err != nil {
+		jsonError(w, "database error: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if !found {
 		jsonError(w, "user not found", http.StatusNotFound)
 		return
 	}