feat: manually create and edit batch-cook recipes

recipe-form.tsx previously had no batch-cook awareness at all — editing an
AI-generated batch-cook recipe and saving silently corrupted it (steps lost
their per-dish `appliesTo` tags, recipeBatchDishes rows went stale/orphaned,
since the create/update API schemas and edit-page query never touched them).

Adds a "batch-cook recipe" toggle to the form, an editable dish list (name,
description, fridge days, freezer-friendly/note, day-of instructions), and
per-step dish tagging (click a dish chip to mark which dish(es) that step
advances; empty = shared prep). Renaming a dish propagates to any step
still tagged with the old name instead of orphaning it. Wired through
Create/Update API schemas and the edit page's query/payload.

Verified locally: created a 2-dish batch recipe from scratch through the
real form, confirmed it renders identically to an AI-generated one (grouped
steps, dishes & storage cards), edited it, renamed a dish, reloaded, and
confirmed the step tag followed the rename rather than orphaning.

apps/web/messages/en.json

@@ -660,7 +660,21 @@
     "discardChangesTitle": "Discard changes?",
     "discardChangesDescription": "You have unsaved changes. If you leave now, they will be lost.",
     "keepEditing": "Keep editing",
-    "discardChanges": "Discard changes"
+    "discardChanges": "Discard changes",
+    "batchCookToggle": "This is a batch-cook recipe",
+    "batchCookToggleHelp": "Split this recipe into several dishes cooked together, each with its own storage and reheat guidance.",
+    "dishes": "Dishes",
+    "addDish": "Add dish",
+    "dishName": "Dish name",
+    "dishDescription": "Description",
+    "fridgeDays": "Fridge (days)",
+    "freezerFriendly": "Freezer-friendly",
+    "freezerNote": "Freezer note",
+    "dayOfInstructions": "Day-of instructions",
+    "dishesRequired": "Add at least one dish",
+    "dayOfInstructionsRequired": "Every dish needs day-of instructions",
+    "appliesTo": "Applies to",
+    "sharedPrep": "Shared prep"
   },
   "canCook": {
     "title": "What can I cook?",