Saudi Coffee image cleanup + shrink "Add notes" toggle (Task #395)

Two small follow-ups on Task #394 polish:

1. Regenerated artifacts/tx-os/public/service-images/saudi-coffee.png
   with a tighter prompt — just the brass dallah pouring brown
   coffee into a small white finjan, soft beige background, no
   dates/cardamom/garnish. Same path so no DB change needed.
2. Shrunk the "إضافة ملاحظات / Add notes" toggle in
   OrderServiceModal: replaced the chunky outline Button with a
   small ghost text-link style (text-xs, muted, pencil icon size 12,
   underline-on-hover). It now reads as a secondary affordance and
   sits below the service-preview row, well clear of the dialog's
   absolute close (X) at right-4 top-4 — no overlap in either AR or
   EN.

Behavior unchanged: data-testid="order-notes-toggle" preserved,
tapping still expands and focuses the textarea, hide link still
collapses without losing typed text.

Verification:
- pnpm --filter @workspace/tx-os typecheck → passes.
- The pre-existing `test` workflow failure is unrelated to this
  change.

artifacts/tx-os/src/components/order-service-modal.tsx

@@ -156,17 +156,15 @@ export function OrderServiceModal({
             </div>
           </div>
         ) : (
-          <Button
+          <button
             type="button"
-            variant="outline"
-            size="sm"
             onClick={handleToggleNotes}
-            className="self-start gap-2"
+            className="self-start inline-flex items-center gap-1.5 text-xs text-muted-foreground hover:text-foreground underline-offset-2 hover:underline -mt-1"
             data-testid="order-notes-toggle"
           >
-            <Pencil size={14} />
+            <Pencil size={12} />
             {t("services.addNotes")}
-          </Button>
+          </button>
         )}
 
         <DialogFooter className="gap-2 sm:gap-2">