refactor(server/api): resolveByID helper for parseUUID->fetch->404 (T4)

internal/api/admin_users.go

@@ -212,20 +212,11 @@ func (h *handlers) handleAdminDeleteUser(w http.ResponseWriter, r *http.Request)
 		writeErr(w, apierror.Unauthorized("auth_required", ""))
 		return
 	}
-	targetID, ok := parseUUID(chi.URLParam(r, "id"))
-	if !ok {
-		writeErr(w, apierror.BadRequest("invalid_id", ""))
-		return
-	}
 
 	q := dbq.New(h.pool)
-	target, err := q.GetUserByID(r.Context(), targetID)
-	if err != nil {
-		if errors.Is(err, pgx.ErrNoRows) {
-			writeErr(w, &apierror.Error{Status: http.StatusNotFound, Code: "not_found", Message: ""})
-			return
-		}
-		writeErrWithLog(w, h.logger, "admin delete user: lookup failed", apierror.Internal(err))
+	target, apiErr := resolveByID(r, "id", q.GetUserByID, "user")
+	if apiErr != nil {
+		writeErr(w, apiErr)
 		return
 	}
 
@@ -243,12 +234,12 @@ func (h *handlers) handleAdminDeleteUser(w http.ResponseWriter, r *http.Request)
 		}
 	}
 
-	if err := q.DeleteUser(r.Context(), targetID); err != nil {
+	if err := q.DeleteUser(r.Context(), target.ID); err != nil {
 		writeErrWithLog(w, h.logger, "admin delete user: delete failed", apierror.Internal(err))
 		return
 	}
 
-	if err := audit.Write(r.Context(), h.pool, caller.ID, targetID, audit.ActionDeleteUser,
+	if err := audit.Write(r.Context(), h.pool, caller.ID, target.ID, audit.ActionDeleteUser,
 		map[string]any{"username": target.Username, "was_admin": target.IsAdmin}); err != nil {
 		h.logger.Warn("admin delete user: audit failed", "err", err)
 	}