feat: garden care reminder bodies, task sync, upload cleanup

- care reminders now fire with plant-specific body ("Time to water Pothos")
  via title/body columns on the reminders table (migration 0016)
- bi-directional task sync: checking off a garden-linked task list item
  creates a care log; logging care from garden marks the linked task done
  (list_items.metadata stores gardenPlantId + gardenCareType linkage)
- upload error response no longer leaks debug detail; error message
  corrected from "5 MB" to "100 MB"

src/modules/_core/schema.ts

@@ -166,6 +166,8 @@ export const reminders = pgTable(
     entityId: uuid("entity_id").notNull(),
     fireAt: timestamp("fire_at", { withTimezone: true }).notNull(),
     channel: text("channel").notNull().default("auto"),
+    title: text("title"),
+    body: text("body"),
     firedAt: timestamp("fired_at", { withTimezone: true }),
     createdBy: uuid("created_by").references(() => users.id, { onDelete: "set null" }),
     createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),