Fix Linux AppImage build: add APPIMAGE_EXTRACT_AND_RUN=1

linuxdeploy is an AppImage itself and needs FUSE to run. GitHub Actions
runners don't always have working FUSE support. Setting this env var
tells AppImage tools to extract-and-run instead, avoiding the FUSE
dependency.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/desktop-release.yml

@@ -338,6 +338,7 @@ jobs:
           TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
           TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY_PASSWORD }}
           NO_STRIP: "true"
+          APPIMAGE_EXTRACT_AND_RUN: "1"
         with:
           projectPath: packages/desktop
           tagName: ${{ env.RELEASE_TAG }}
@@ -345,7 +346,7 @@ jobs:
           releaseBody: See the assets to download and install this version.
           releaseDraft: ${{ env.RELEASE_DRAFT }}
           prerelease: false
-          args: --bundles appimage --verbose
+          args: --bundles appimage
 
       - name: Build Linux app (smoke only)
         if: env.IS_SMOKE_TAG == 'true'