fix(ext-ui): direct :href install button (Firefox needs anchor click, not programmatic navigation) + manifest version detection ignores -latest.xpi alias — Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/settings/BrowserExtensionCard.vue

@@ -34,11 +34,18 @@
 
       <template v-else-if="manifest?.installed">
         <div class="fc-ext-install mt-3">
+          <!-- Install button: direct :href anchor click (no programmatic
+               window.location.assign). Firefox's XPI-install gesture
+               requires a user-clicked anchor pointing at an
+               application/x-xpinstall response; programmatic navigation
+               sometimes triggered nothing instead of the install dialog
+               (operator-flagged 2026-05-26). No `download` attribute —
+               that would force a save dialog instead of install. -->
           <v-btn
             v-if="isFirefox"
             color="accent" variant="flat" rounded="pill"
             prepend-icon="mdi-firefox"
-            @click="installXpi"
+            :href="manifest.latest_url"
           >Install Firefox extension</v-btn>
 
           <v-btn
@@ -146,11 +153,6 @@ async function loadKey() {
   }
 }
 
-function installXpi() {
-  if (!manifest.value?.latest_url) return
-  window.location.assign(manifest.value.latest_url)
-}
-
 async function rotateKey() {
   rotating.value = true
   try {