Drop a pending Regular's link when it is renamed

A Regular added from a recipe link stores recipe_url, and its grounding job
grounds that link. Renaming the dinner while still pending kept the link, so
the job queued for the new name still attached the old link's recipe and
photo. UpdateDinner now sets recipe_url, and renaming a pending dinner
clears it: the fresh job grounds the new name by search, and the household
can give a link by hand to fix up the recipe if they want a specific one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/dinners/dinners.go

@@ -294,8 +294,9 @@ func (s *Service) List(ctx context.Context, status string) ([]Dinner, error) {
 // Update applies p to dinner id, recording updatedBy. An invalid patch is a
 // *ValidationError and a new name repeating another unarchived dinner a
 // *DuplicateError; either changes nothing. Renaming a dinner still pending
-// enqueues a fresh KindGroundDinner job for the new name: the job already
-// running was for the old name, and its result no longer applies.
+// clears its recipe_url and enqueues a fresh KindGroundDinner job that
+// grounds the new name: the job already running was for the old name or
+// link, and its result no longer applies.
 func (s *Service) Update(ctx context.Context, id string, p Patch, updatedBy string) (Dinner, error) {
 	if updatedBy == "" {
 		return Dinner{}, errors.New("dinners: update: no member to record as updated_by")
@@ -327,6 +328,7 @@ func (s *Service) Update(ctx context.Context, id string, p Patch, updatedBy stri
 			Difficulty:      cur.Difficulty,
 			Cuisine:         cur.Cuisine,
 			RecipeID:        cur.RecipeID,
+			RecipeUrl:       cur.RecipeUrl,
 			PhotoID:         cur.PhotoID,
 			GroundingStatus: cur.GroundingStatus,
 			UpdatedBy:       sql.NullString{String: updatedBy, Valid: true},
@@ -338,6 +340,11 @@ func (s *Service) Update(ctx context.Context, id string, p Patch, updatedBy stri
 			}
 			params.Name = name
 			params.NormalizedName = harness.Normalize(name)
+			if cur.GroundingStatus == GroundingPending && params.NormalizedName != cur.NormalizedName {
+				// The link was the old dinner's recipe; the new name is
+				// grounded by name, and a link can be given by hand.
+				params.RecipeUrl = sql.NullString{}
+			}
 		}
 		if p.Method != nil {
 			params.Method = sql.NullString{String: *p.Method, Valid: true}