feat(updates): titlebar update indicator + dev injectors for the update flow

- light up the Phokus iris's focal point (pulsing amber) in the titlebar when
  an update is pending; click goes straight to install, with a fast custom
  tooltip (native title delay was too slow)
- PhokusMark gains an optional dotClassName to render the central focal point
- DemoPanel: inject every updater state (available/downloading/installing/
  error/up-to-date), which is otherwise unreachable without a remote latest.json

src/components/PhokusMark.tsx

@@ -3,9 +3,18 @@
 //   <PhokusMark className="h-4 w-4 text-gray-300" />
 // The full app-icon tile (filled iris on a dark rounded square) lives in
 // branding/phokus-aperture.svg and feeds `pnpm tauri icon`.
+//
+// Pass dotClassName (e.g. "fill-amber-400") to light up the central focal point —
+// used in the titlebar as the "update available" indicator.
 const BLADE = "M0,-4.18 A10,10 0 0 1 6.43,-7.66";
 
-export function PhokusMark({ className }: { className?: string }) {
+export function PhokusMark({
+  className,
+  dotClassName,
+}: {
+  className?: string;
+  dotClassName?: string;
+}) {
   return (
     <svg viewBox="0 0 24 24" fill="none" className={className}>
       <g
@@ -24,6 +33,7 @@ export function PhokusMark({ className }: { className?: string }) {
         <path d={BLADE} transform="rotate(240)" />
         <path d={BLADE} transform="rotate(300)" />
       </g>
+      {dotClassName ? <circle cx="12" cy="12" r="2.6" stroke="none" className={dotClassName} /> : null}
     </svg>
   );
 }