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>

docs/ARCHITECTURE.md

@@ -470,6 +470,20 @@ automatic** (D-021).
   not a Regular; and one whose reason is over 180 characters or names none
   of its cited Regulars. Cited names are rewritten as the household writes
   them. Grounding each survivor in a recipe is the caller's next step.
+- **Supply run titles** (`skills.TitleArchive`, skill `archive_title`
+  v1): from the names of the week's planned dinners in day order, writes
+  `{title}`, the Supply run's post title in the Supply archive, at the
+  household temperature with no household context. A title must be 1–48
+  characters on one line, with no emoji and no surrounding quotation
+  marks; a reply breaking a rule gets the one repair turn, never a
+  truncation. `shopping.Generate` (and `GeneratePushed`) runs it after
+  storing a list that is still untitled — a new list, or one a failed
+  title left untitled — outside the generation's transaction, and writes
+  `shopping_lists.title` only while the list is untitled and not frozen.
+  A title is written once; a remake keeps it. A failed title never fails
+  the generation: the list stays untitled (the UI shows the week label),
+  the failure is logged as a warning and recorded in `ai_runs`, and the
+  week's next generation tries again.
 
 ## Recipe grounding