feat: add logo and polish icon presentation

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

extension/src/popup/components/unlock.ts

@@ -8,6 +8,7 @@ export function renderUnlock(app: HTMLElement): void {
 
   app.innerHTML = `
     <div class="pad" style="text-align:center; padding-top:40px;">
+      <img class="brand-logo" src="icons/idfoto-logo.svg" alt="">
       <div class="brand">idfoto</div>
       <p class="muted" style="margin:8px 0 24px;">two-factor vault</p>
       <div class="form-group">