Add the archive_title skill and title Supply runs on generation

archive_title v1 writes a Supply run's post title for the Supply archive
from the week's dinner names in day order. Validation requires 1-48
characters on one line, no emoji and no surrounding quotation marks; a
reply breaking a rule gets the harness's one repair turn.

shopping.Generate and GeneratePushed run it, outside the generation's
transaction, whenever the stored list is still untitled, and store
shopping_lists.title only while the list is untitled and not frozen. A
title failure never fails the generation: the list stays untitled, the
failure is logged and recorded in ai_runs, and the week's next
generation tries again. A titled list keeps its title on remakes.

Maestro task fa4b94c9-6623-41ab-8d2a-0ca7d1e6401a.

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

internal/server/server_test.go

@@ -211,16 +211,22 @@ func newTestPlan(t *testing.T) *plan.Service {
 }
 
 // newTestShopping returns a shopping service over a migrated temp
-// database.
+// database, whose Supply runs stay untitled.
 func newTestShopping(t *testing.T) *shopping.Service {
 	t.Helper()
-	svc, err := shopping.NewService(newTestStore(t))
+	svc, err := shopping.NewService(newTestStore(t), untitled, slog.New(slog.NewTextHandler(io.Discard, nil)))
 	if err != nil {
 		t.Fatal(err)
 	}
 	return svc
 }
 
+// untitled is a shopping.Titler with no model: every Supply run it is
+// asked to title stays untitled.
+func untitled(context.Context, string, skills.ArchiveTitleRequest) (skills.ArchiveTitle, error) {
+	return skills.ArchiveTitle{}, errors.New("no model in this test")
+}
+
 // newTestBox returns a secret box under a random key.
 func newTestBox(t *testing.T) *secretbox.Box {
 	t.Helper()