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/grounding_test.go

@@ -349,6 +349,44 @@ func TestRenameWhilePendingGroundsNewName(t *testing.T) {
 	}
 }
 
+// TestRenameLinkWhilePendingGroundsNewName: a Regular added from a link and
+// renamed while still pending drops the link and grounds its new name, not
+// the old link's recipe and photo.
+func TestRenameLinkWhilePendingGroundsNewName(t *testing.T) {
+	t.Parallel()
+	e := newUnstartedEnv(t)
+	e.search.Results["Beef stew"] = []recipes.Candidate{{URL: stew}}
+	e.model.QueueGenerate(recipestest.NormalizedReply("oven", 150))
+
+	c, err := e.svc.CreateRegular(t.Context(), dinners.NewRegular{RecipeURL: ptr(curryA)}, member)
+	if err != nil {
+		t.Fatal(err)
+	}
+	d, err := e.svc.Update(t.Context(), c.ID, dinners.Patch{Name: ptr("Beef stew")}, member)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d.GroundingStatus != dinners.GroundingPending || d.RecipeURL != nil {
+		t.Fatalf("renamed = %+v, want still pending with no recipe_url", d)
+	}
+	e.start(t)
+
+	row := e.waitGrounding(t, c.ID)
+	if row.GroundingStatus != dinners.GroundingGrounded {
+		t.Fatalf("dinner = %+v, want grounded for the new name", row)
+	}
+	rec, err := db.New(e.st.Reader).GetRecipe(t.Context(), row.RecipeID.String)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rec.SourceUrl != stew || rec.PhotoID != row.PhotoID || row.Method.String != "oven" || row.MinutesTotal.Int64 != 150 {
+		t.Errorf("dinner = %+v recipe %s, want grounded in %s, not the old link %s", row, rec.SourceUrl, stew, curryA)
+	}
+	if got := e.search.Queries(); !slices.Equal(got, []string{"Beef stew"}) {
+		t.Errorf("searched %q, want only the new name", got)
+	}
+}
+
 // TestRenameWhilePendingEnqueueFailure: a pending Regular renamed when the
 // job for its new name cannot be enqueued is failed, not left pending.
 func TestRenameWhilePendingEnqueueFailure(t *testing.T) {