feat(smartsheet): cycle 7 — workbook hub

Replaces two independent Smartsheet configs (water log + time tracking)
with one brand-level workbook connection that owns the encrypted API
token. Per-feature configs keep their sheet_id + column_mapping +
frequency + sync_enabled.

Schema (migration 0096):
- NEW smartsheet_workspace: one row per brand. Holds encrypted_api_token
  + token_iv + token_auth_tag (AES-256-GCM, same key), default_sheet_id,
  connection_enabled (master switch), last_test_*, audit columns. RLS
  brand-scoped.
- Backfill: water_smartsheet_config rows copy into workspace first;
  time_tracking_smartsheet_config fills in only brands with no workspace
  row yet. Idempotent (NOT EXISTS + ON CONFLICT DO NOTHING).
- DROP encrypted_api_token + token_iv + token_auth_tag from both feature
  configs (destructive — bytes are copied to workspace first).
- Drop unused bytea customType from both schemas (no longer needed).

Actions:
- NEW src/actions/smartsheet/workspace.ts: getSmartsheetWorkspace,
  saveSmartsheetWorkspace, testSmartsheetWorkspaceConnection,
  disableSmartsheetWorkspace. Permission: can_manage_settings +
  platform_admin.
- NEW src/services/workspace-token.ts (server-only): resolveWorkspaceToken
  helper. Lives outside the 'use server' file so the plaintext token
  is not exposed as an RPC surface — only callable from server-side
  sync engines.
- MODIFIED water-log + time-tracking smartsheet actions: refactored to
  read token via resolveWorkspaceToken; save* no longer accepts a
  token; test* falls through to the workspace token if no token given.
- MODIFIED both sync services: load token from resolveWorkspaceToken
  instead of decrypting the per-feature config. 'connection_disabled'
  now skips cleanly (no retry, no failed log row) — pausing the
  workspace at the hub level no longer floods Recent Activity with
  'disabled' failures.

UI:
- NEW src/components/admin/water-log/SmartsheetHub.tsx: top-level hub
  card. Owns the token + Test Connection + connection enabled toggle +
  default sheet ID + last-verified badge. Permission gated.
- MODIFIED SmartsheetIntegrationCard.tsx (water): rewritten without
  token UI. Reads masked token from workspace. Sheet ID + column
  mapping + frequency + enabled + backfill + recent activity.
- MODIFIED TimeTrackingSmartsheetCard.tsx: same treatment.
- MODIFIED /admin/water-log/settings/page: collapses §05 + §06 into a
  single Smartsheet section with the hub on top + both feature cards
  as siblings underneath.

Tuxedo-only throughout (TUXEDO_BRAND_ID hardcoded in the settings
page; matches existing single-tenant /water convention).

Security fixes from pr-reviewer:
- resolveWorkspaceToken extracted from 'use server' file to a
  server-only service module — was reachable as an RPC, would have
  returned the plaintext token to any authenticated admin.
- getSmartsheetWorkspace now actually checks the auth result instead
  of calling requireManageSettings() and discarding the return value.

Diff: -1742 / +597 lines (net -1100 from the simpler per-feature card).

db/schema/water-log.ts

@@ -24,18 +24,14 @@ import {
   index,
   uniqueIndex,
   integer,
-  customType,
 } from "drizzle-orm/pg-core";
 import { brands } from "./brands";
 import { adminUsers } from "./brands";
 
-// Drizzle's stock `bytea` import is not exported in every version, so
-// register a small custom type that maps to the existing `bytea` PG type.
-const bytea = customType<{ data: Buffer; default: false }>({
-  dataType() {
-    return "bytea";
-  },
-});
+// Cycle 7: the `bytea` customType used to live here for the
+// encrypted Smartsheet token columns. Those columns moved to
+// `smartsheet_workspace` (see `db/schema/smartsheet-workspace.ts`),
+// so the helper is no longer needed here.
 
 export const waterHeadgates = pgTable(
   "water_headgates",
@@ -323,9 +319,8 @@ export const waterSmartsheetConfig = pgTable("water_smartsheet_config", {
     .primaryKey()
     .references(() => brands.id, { onDelete: "cascade" }),
   sheetId: text("sheet_id").notNull(),
-  encryptedApiToken: bytea("encrypted_api_token").notNull(),
-  tokenIv: bytea("token_iv").notNull(),
-  tokenAuthTag: bytea("token_auth_tag").notNull(),
+  // Cycle 7: encrypted token columns moved to smartsheet_workspace.
+  // See migration 0096_smartsheet_workbook_hub.sql.
   columnMapping: jsonb("column_mapping")
     .$type<SmartsheetColumnMapping>()
     .notNull(),