feat(branding): replace default Tauri icon with the Phokus aperture mark

- regenerate src-tauri/icons from the new branding/phokus-aperture.svg master
- add reusable PhokusMark component (inline SVG, inherits currentColor)
- use it for the titlebar app mark, retiring the placeholder

src/components/PhokusMark.tsx

@@ -0,0 +1,29 @@
+// Phokus brand mark — a camera iris, rendered inline so it inherits `currentColor`
+// and scales to any size. Drive color + dimensions from the className, e.g.
+//   <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`.
+const BLADE = "M0,-4.18 A10,10 0 0 1 6.43,-7.66";
+
+export function PhokusMark({ className }: { className?: string }) {
+  return (
+    <svg viewBox="0 0 24 24" fill="none" className={className}>
+      <g
+        transform="translate(12 12)"
+        stroke="currentColor"
+        strokeWidth="1.5"
+        strokeLinecap="round"
+        strokeLinejoin="round"
+      >
+        <circle r="10" />
+        <path d="M0,-4.18 A4.73,4.73 0 0 0 3.62,-2.09 A4.73,4.73 0 0 0 3.62,2.09 A4.73,4.73 0 0 0 0,4.18 A4.73,4.73 0 0 0 -3.62,2.09 A4.73,4.73 0 0 0 -3.62,-2.09 A4.73,4.73 0 0 0 0,-4.18 Z" />
+        <path d={BLADE} />
+        <path d={BLADE} transform="rotate(60)" />
+        <path d={BLADE} transform="rotate(120)" />
+        <path d={BLADE} transform="rotate(180)" />
+        <path d={BLADE} transform="rotate(240)" />
+        <path d={BLADE} transform="rotate(300)" />
+      </g>
+    </svg>
+  );
+}

src/components/TitleBar.tsx

@@ -1,6 +1,7 @@
 import { useState, useEffect } from "react";
 import { getCurrentWindow } from "@tauri-apps/api/window";
 import { useGalleryStore } from "../store";
+import { PhokusMark } from "./PhokusMark";
 
 // SVG icons for window controls
 function MinimizeIcon() {
@@ -69,12 +70,8 @@ export function TitleBar() {
     >
       {/* App icon + name — left side */}
       <div className="flex items-center gap-2 pl-3 pr-4">
-        <div className="flex h-5 w-5 items-center justify-center rounded-md bg-white/8 overflow-hidden">
-          {/* Phokus logo placeholder — replace with <img src={logo} /> if you have an SVG */}
-          <svg width="12" height="12" viewBox="0 0 12 12" fill="none">
-            <circle cx="6" cy="6" r="4" stroke="#a78bfa" strokeWidth="1.5" />
-            <circle cx="6" cy="6" r="1.5" fill="#a78bfa" />
-          </svg>
+        <div className="flex h-5 w-5 items-center justify-center rounded-md bg-white/8 overflow-hidden text-gray-300">
+          <PhokusMark className="h-4 w-4" />
         </div>
         <span className="text-[11px] font-semibold text-gray-400 tracking-wide">Phokus</span>
       </div>