wip(intake): router, enrich endpoint, Slack handlers, migration 0034 — UNTESTED checkpoint

Agent was terminated by the session usage limit before running lint/tests or
writing its report. Files are complete drafts against plan §11 (C1, C2, C5):
src/app/api/intake/, src/app/api/transactions/[id]/line-items/, src/lib/intake-*.ts,
src/lib/line-items.ts, prisma/migrations/0034_intake_batches, fixtures + tests.
Next: npm ci && npx prisma generate && npm run lint && npm test && npm run test:integration.

prisma/schema.prisma

@@ -268,3 +268,28 @@ model rule_apply_runs {
   reverted_at           DateTime?
   snapshot              Json      @default("[]")
 }
+
+// 0034 — intake router. One row per upload batch, written before extraction so
+// Slack taps can act on it later and a re-share is detected. Columns are the
+// §11 C1 contract in plans/intake-router-slice-plan.md (smarthome repo).
+model intake_batches {
+  id             String    @id @db.Uuid
+  source         String
+  shared_by      String?
+  file_sha256    String[]  @default([])
+  header         Json?
+  items          Json?
+  kind           String?
+  status         String
+  transaction_id Int?
+  capture_id     Int?
+  created_at     DateTime  @default(now()) @db.Timestamptz(6)
+  resolved_at    DateTime? @db.Timestamptz(6)
+}
+
+// 0034 — the remembered answer to "Groceries or a meal?" per merchant.
+model intake_merchant_kinds {
+  merchant_key String   @id
+  kind         String
+  created_at   DateTime @default(now()) @db.Timestamptz(6)
+}