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/plans_test.go

@@ -80,7 +80,7 @@ func newPlansRouter(t *testing.T) plansEnv {
 	if err != nil {
 		t.Fatal(err)
 	}
-	shop, err := shopping.NewService(st)
+	shop, err := shopping.NewService(st, untitled, logger)
 	if err != nil {
 		t.Fatal(err)
 	}