feat(whats-new): release 6 covers supplier payments and the theme picker

The payments and approvals queue, the theme rework and the release
number on the popup all landed since release 5, so the office is told
about them in one place.

The entry is the release number and the commit, never a date, and the
popup still renders no date of any kind.

src/lib/release-notes.ts

@@ -36,6 +36,20 @@ export interface ReleaseNote {
 }
 
 export const RELEASE_NOTES: ReleaseNote[] = [
+  {
+    release: 6,
+    commit: "4eb6ebf",
+    date: "2026-11-05",
+    title: "Supplier payments and approvals, and a theme picker that tells the truth",
+    items: [
+      "Payments and Approvals — a new page under Orders. Flag an order item that needs paying and it lands in one queue with the customer, the supplier and the items it covers.",
+      "Attach the supplier's invoice or pro forma to the request. The buyer's purchase order is linked for you, so nothing gets downloaded and uploaded twice.",
+      "Mark it paid with a proof of payment attached. Until it is paid, that item cannot be marked ready for collection or go out with a driver.",
+      "Approvals live on the same page. Items waiting on a markup decision show the cost, the selling price and the markup, with a link straight to the item.",
+      "The theme picker now previews the colours the app actually uses, so a palette card cannot promise a colour the product does not paint. Every palette has a proper dark surface, and a retired theme falls back to the default instead of an unstyled page.",
+      "This popup now carries a release number and the commit it shipped with, and no dates.",
+    ],
+  },
   {
     release: 5,
     commit: "139ea25",