Guard recipe repairs against same-normalized renames and member edits

F1-1: GroundDinner also compares the observed raw name, so renaming
"Grandma's stew" to "Easy Grandma's stew" (same normalized_name) while a
link is grounding is ErrGroundConflict, not attached to the renamed
dinner.

F1-2: A method, minutes_total or difficulty no longer as observed before
grounding is kept over the recipe's value, as GroundPendingDinner keeps
values a member set while a dinner was pending.

F2-1: Failing to record a grounded candidate or link on the dinner (or to
read it back after a rejected write) wraps ErrGroundFailed, so the API
logs reason=ground_failed with the dinner id, never the database error.

Maestro task 8741cedb-1849-4e3f-8d05-f5648c77c7ee.

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

internal/dinners/grounding_test.go

@@ -1126,6 +1126,13 @@ func TestFixInFlightWhenDinnerChanges(t *testing.T) {
 		}, dinners.ErrGroundConflict, func(row db.Dinner) bool {
 			return row.Name == "Chicken curry" && row.GroundingStatus == dinners.GroundingFailed && !row.RecipeID.Valid
 		}},
+		{"renamed to the same normalized name", func(t *testing.T, e *env, id string) {
+			if _, err := e.svc.Update(t.Context(), id, dinners.Patch{Name: ptr("Easy Grandma's stew")}, member); err != nil {
+				t.Fatal(err)
+			}
+		}, dinners.ErrGroundConflict, func(row db.Dinner) bool {
+			return row.Name == "Easy Grandma's stew" && row.GroundingStatus == dinners.GroundingFailed && !row.RecipeID.Valid
+		}},
 		{"archived", func(t *testing.T, e *env, id string) {
 			if _, err := e.svc.Archive(t.Context(), id, member); err != nil {
 				t.Fatal(err)
@@ -1170,6 +1177,40 @@ func TestFixInFlightWhenDinnerChanges(t *testing.T) {
 	}
 }
 
+// TestFixInFlightKeepsMemberEdits: a method or difficulty a member sets
+// while a link is grounding is kept; what they left alone takes the link's
+// recipe.
+func TestFixInFlightKeepsMemberEdits(t *testing.T) {
+	t.Parallel()
+	e := newEnv(t)
+	id := failedDinner(t, e, "Grandma's stew")
+	e.model.QueueGenerate(recipestest.NormalizedReply("oven", 150))
+	e.pages.Gate = make(chan struct{})
+
+	done := make(chan error, 1)
+	go func() {
+		_, err := e.svc.Ground(context.Background(), id, dinners.Fix{RecipeURL: ptr(stew)}, member)
+		done <- err
+	}()
+	e.waitFetched(t, stew)
+	if _, err := e.svc.Update(t.Context(), id, dinners.Patch{Method: ptr("grill"), Difficulty: ptr("easy")}, member); err != nil {
+		t.Fatal(err)
+	}
+	close(e.pages.Gate)
+
+	if err := <-done; err != nil {
+		t.Fatal(err)
+	}
+	row := e.dinner(t, id)
+	if row.GroundingStatus != dinners.GroundingGrounded || !row.RecipeID.Valid {
+		t.Errorf("dinner = %+v, want grounded in the link's recipe", row)
+	}
+	if row.Method.String != "grill" || row.Difficulty.String != "easy" || row.MinutesTotal.Int64 != 150 {
+		t.Errorf("method, difficulty, minutes = %q, %q, %d; want grill and easy kept, 150 from the recipe",
+			row.Method.String, row.Difficulty.String, row.MinutesTotal.Int64)
+	}
+}
+
 // TestFixArchivedDinner: an archived dinner cannot be grounded by hand.
 func TestFixArchivedDinner(t *testing.T) {
 	t.Parallel()