Replace APPIMAGE_EXTRACT_AND_RUN with pre-extracted linuxdeploy wrapper

Docker CI containers lack FUSE kernel module, and the env var approach
was unreliable when Tauri spawns linuxdeploy as a subprocess.

Instead: download linuxdeploy-x86_64.AppImage, extract its squashfs
content using squashfs-tools (no FUSE needed), then place a shell
wrapper at ~/.cache/tauri/linuxdeploy-x86_64.AppImage so Tauri uses
the extracted binary directly without AppImage runtime.

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

.gitea/workflows/release.yml

@@ -135,7 +135,7 @@ jobs:
             librsvg2-dev \
             patchelf \
             xdg-utils \
-            libfuse2
+            squashfs-tools
 
       - uses: dtolnay/rust-toolchain@stable
 
@@ -152,18 +152,30 @@ jobs:
       - name: Install Tauri deps
         run: npm ci
 
-      - name: Stage AppRun for AppImage bundler
+      - name: Stage AppRun and linuxdeploy for AppImage bundler
         run: |
           mkdir -p ~/.cache/tauri
           cp tools/AppRun-x86_64 ~/.cache/tauri/AppRun-x86_64
           chmod +x ~/.cache/tauri/AppRun-x86_64
+          # Pre-extract linuxdeploy AppImage so it runs without FUSE in Docker
+          wget -q \
+            "https://github.com/tauri-apps/binary-releases/releases/download/linuxdeploy/linuxdeploy-x86_64.AppImage" \
+            -O /tmp/linuxdeploy.AppImage
+          OFFSET=$(python3 -c "
+d=open('/tmp/linuxdeploy.AppImage','rb').read()
+o=d.find(b'hsqs')
+print(o if o!=-1 else d.find(b'sqsh'))
+")
+          unsquashfs -d /tmp/linuxdeploy-root -offset "$OFFSET" /tmp/linuxdeploy.AppImage
+          printf '#!/bin/sh\nexec /tmp/linuxdeploy-root/AppRun "$@"\n' \
+            > ~/.cache/tauri/linuxdeploy-x86_64.AppImage
+          chmod +x ~/.cache/tauri/linuxdeploy-x86_64.AppImage
 
       - name: Build
         env:
           TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
           TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ''
           NODE_OPTIONS: '--max_old_space_size=4096'
-          APPIMAGE_EXTRACT_AND_RUN: '1'
         run: npm run tauri -- build --bundles appimage,deb
 
       - name: Upload to release