fix(W1): self-write-back suppression via old/new field comparison

- Replace brittle sync_status==='synced' loop guard with NocoDB v2
  old/new row comparison (previous_rows vs rows).
- businessChanged() = business field move OR sync_required set; echo
  (bookkeeping-only delta) -> skip_writeback_echo, zero AList mutation.
- writeBack() value-change guard: GET live record, PATCH only fields
  whose value actually changes (no-change -> no PATCH -> no webhook).
- sync_required Checkbox honored as force-reprocess flag, cleared on write-back.
- Extract-id node passes previousRow/newRow through Load Env to lifecycle.
- W1 lifecycle test now covers echo suppression (26 assertions).
- Customers.status still NOT consumed by permission calc (TBD semantics).
- W2/W3 effective-grants semantics unchanged.

n8n/gen_w1.js

@@ -27,7 +27,7 @@ const workflow = {
     },
     {
       parameters: {
-        jsCode: "const body = $input.item.json.body ?? $input.item.json;\nconst data = body.data ?? {};\nconst rows = data.rows?.[0] ?? data.previous_rows?.[0] ?? data.rows_new?.[0] ?? data.rows_old?.[0] ?? {};\nconst id = rows.Id ?? data.data?.rows?.[0]?.Id;\nif (!id) throw new Error('no customer Id in webhook');\nreturn { json: { customerId: Number(id), eventType: body.type ?? '' } };\n"
+        jsCode: "const body = $input.item.json.body ?? $input.item.json;\nconst data = body.data ?? {};\n// NocoDB v2: data.rows = post-update rows, data.previous_rows = pre-update rows.\nconst newRows = data.rows ?? data.rows_new ?? [];\nconst oldRows = data.previous_rows ?? data.rows_old ?? [];\nconst newRow = newRows[0] ?? {};\nconst oldRow = oldRows[0] ?? {};\nconst id = newRow.Id ?? oldRow.Id;\nif (!id) throw new Error('no customer Id in webhook');\nreturn { json: { customerId: Number(id), eventType: body.type ?? '', previousRow: oldRow, newRow } };\n"
       },
       id: 'extract-id',
       name: 'Extract Customer Record Id',
@@ -37,7 +37,7 @@ const workflow = {
     },
     {
       parameters: {
-        jsCode: "// pass-through env + webhook fields (custom env vars readable ONLY via $env here)\nconst prev = $input.item.json;\nreturn { json: {\n  customerId: prev.customerId,\n  eventType: prev.eventType,\n  NOCODB_URL: $env.NOCODB_URL,\n  NOCODB_TOKEN: $env.NOCODB_TOKEN,\n  NOCODB_TABLE_CUSTOMERS: $env.NOCODB_TABLE_CUSTOMERS,\n  NOCODB_TABLE_CUSTOMERPRODUCTS: $env.NOCODB_TABLE_CUSTOMERPRODUCTS,\n  NOCODB_TABLE_PRODUCTS: $env.NOCODB_TABLE_PRODUCTS,\n  NOCODB_TABLE_RESOURCES: $env.NOCODB_TABLE_RESOURCES,\n  NOCODB_TABLE_ACCESSGRANTS: $env.NOCODB_TABLE_ACCESSGRANTS,\n  NOCODB_LINK_PROD_RESOURCES: $env.NOCODB_LINK_PROD_RESOURCES,\n  ALIST_URL: $env.ALIST_URL,\n  ALIST_ADMIN_USERNAME: $env.ALIST_ADMIN_USERNAME,\n  ALIST_ADMIN_PASSWORD: $env.ALIST_ADMIN_PASSWORD,\n} };\n"
+        jsCode: "// pass-through env + webhook fields (custom env vars readable ONLY via $env here)\nconst prev = $input.item.json;\nreturn { json: {\n  customerId: prev.customerId,\n  eventType: prev.eventType,\n  previousRow: prev.previousRow,\n  newRow: prev.newRow,\n  NOCODB_URL: $env.NOCODB_URL,\n  NOCODB_TOKEN: $env.NOCODB_TOKEN,\n  NOCODB_TABLE_CUSTOMERS: $env.NOCODB_TABLE_CUSTOMERS,\n  NOCODB_TABLE_CUSTOMERPRODUCTS: $env.NOCODB_TABLE_CUSTOMERPRODUCTS,\n  NOCODB_TABLE_PRODUCTS: $env.NOCODB_TABLE_PRODUCTS,\n  NOCODB_TABLE_RESOURCES: $env.NOCODB_TABLE_RESOURCES,\n  NOCODB_TABLE_ACCESSGRANTS: $env.NOCODB_TABLE_ACCESSGRANTS,\n  NOCODB_LINK_PROD_RESOURCES: $env.NOCODB_LINK_PROD_RESOURCES,\n  ALIST_URL: $env.ALIST_URL,\n  ALIST_ADMIN_USERNAME: $env.ALIST_ADMIN_USERNAME,\n  ALIST_ADMIN_PASSWORD: $env.ALIST_ADMIN_PASSWORD,\n} };\n"
       },
       id: 'load-env',
       name: 'Load Env',