feat: add batch-cooking sessions (single "mega recipe" with dish sections)

New AI-generated batch-cooking flow: pick N dinners/lunches + servings,
get one unified recipe covering a full prep session — merged shopping
list, steps tagged per-dish (a step can advance several dishes at once,
e.g. a shared oven bake), and per-dish storage (fridge/freezer) + exact
day-of reheat/finishing instructions.

Schema: recipes.isBatchCook, recipeSteps.appliesTo (dish names), new
recipeBatchDishes table. Batch recipes are excluded from the normal
/recipes list and live under their own /batch-cooking section.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

packages/db/src/migrations/meta/_journal.json

@@ -204,6 +204,13 @@
       "when": 1783671061049,
       "tag": "0028_smiling_ezekiel_stane",
       "breakpoints": true
+    },
+    {
+      "idx": 29,
+      "version": "7",
+      "when": 1783810665920,
+      "tag": "0029_tired_crystal",
+      "breakpoints": true
     }
   ]
 }