Address the 11 October test report findings

The initial test report (run before the pilot-readiness changes) raised
seven findings and a retest plan. This closes the ones still open.

- F-01: a business on its free trial may run 2 active branches whatever
  its tier, so an owner can try transfers and per-branch stock. Only
  active branches count towards any limit.
- F-06: owners can rename branches and deactivate/reactivate them from
  the Branches page. A branch can only be deactivated once it holds no
  stock and no active staff; its history stays in every report, and it
  leaves every picker.
- F-04: the Products page lists deactivated products under a toggle with
  Reactivate. Deactivating warns about stock still on hand, which stays
  on the Stock page so it can be transferred or counted out.
- F-05: products carry a unit (L, ml, kg, g, pcs, tray, pack) instead of
  everything being litres.
- CAT-12: product prices must be above zero and names are unique per
  business, ignoring case.
- F-03: a reversed report period is refused by the page and the API, and
  the page labels which period the cards show. Report dates are Nairobi
  business days.
- F-07: cost of goods sold is units sold x average buying price. Stock
  bought in the period is reported separately, with a cash surplus line,
  so unsold stock no longer shows as a loss.
- STA-04: staff and new branch managers can be invited with a one-time,
  7-day link; the person sets their own password. Managers can issue a
  new link for their own cashiers.
- OFF-02 / POS-02: the till shows each product's stock and deducts every
  sale immediately, online or offline; it warns before selling more than
  the recorded stock, and has a Clear sale button.
- npm run backfill:stock turns purchases recorded before the stock ledger
  into stock, so existing tenants (and the report's ZERRO fixtures) start
  from what they bought.

tests/retest-plan.test.ts runs the report's completion and retest plan
and checks every balance and total it predicts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/api/platform/businesses/route.ts

@@ -4,7 +4,7 @@ import { Business } from "@/lib/server/models/Business";
 import { User } from "@/lib/server/models/User";
 import { Branch } from "@/lib/server/models/Branch";
 import { requirePlatformAdmin } from "@/lib/server/platform";
-import { TIERS, type TierId } from "@/lib/tiers";
+import { TIERS, effectiveMaxBranches, type TierId, type SubscriptionStatus } from "@/lib/tiers";
 
 export const runtime = "nodejs";
 export const dynamic = "force-dynamic";
@@ -28,6 +28,7 @@ export async function GET(req: NextRequest) {
       { $group: { _id: "$businessId", count: { $sum: 1 } } },
     ]),
     Branch.aggregate<{ _id: unknown; count: number }>([
+      { $match: { isActive: { $ne: false } } },
       { $group: { _id: "$businessId", count: { $sum: 1 } } },
     ]),
   ]);
@@ -58,7 +59,7 @@ export async function GET(req: NextRequest) {
       userCount: userMap.get(String(b._id)) ?? 0,
       branchCount: branchMap.get(String(b._id)) ?? 0,
       maxUsers: TIERS[tier].maxUsers,
-      maxBranches: TIERS[tier].maxBranches,
+      maxBranches: effectiveMaxBranches(tier, (b.subscriptionStatus as SubscriptionStatus) ?? "TRIALING"),
       owner: owner
         ? { name: owner.name, email: owner.email, phoneNumber: owner.phoneNumber }
         : null,