list: drop confusing 'clear' button + bump enrich timeout 90→180s

(1) /list had a 'clear' button that just unchecked all the localStorage
shopping checkboxes. Cobb correctly flagged it as confusing — looks
like a destructive action ('clear what?'). It was just a UX nicety
for re-using the same shopping list, not a plan-touching operation.
The plan-level reset already lives on /plan via a properly-scoped
button. Removing the /list 'clear' so there's exactly one reset
concept in the app: /plan → ⌫ reset week.

(2) forge.enrich_recipe was hitting clawdforge with timeout_secs=90
which proved too short for one recipe (peppery-barbecue-glazed-shrimp
type long ingredient list). Bumped to 180s to match the sterilizer's
post-fix timeout. Walks now have more slack before timing out a single
recipe.

cauldron/forge.py

@@ -650,7 +650,7 @@ class Forge:
             "'chicken stir fry with rice'.\n"
             "- When uncertain on a categorical, use 'unknown' or 'other' rather than guessing."
         )
-        result = self.run(prompt, model=model or "sonnet", timeout_secs=90)
+        result = self.run(prompt, model=model or "sonnet", timeout_secs=180)
         return _extract_recipe_meta(result)
 
     def fetch_food_info(self, name: str, *, model: str | None = None) -> dict: