feat: add linux flatpack build

Author: belnadris

.github/workflows/ubuntu.yml

@@ -54,7 +54,9 @@ jobs:
     - name: Install linux dependencies
       run: |
         sudo apt-get update
-        sudo apt-get install -y libgtk-3-dev webkit2gtk-4.0 libappindicator3-dev librsvg2-dev patchelf
+        sudo apt-get install -y libgtk-3-dev webkit2gtk-4.0 libappindicator3-dev librsvg2-dev patchelf flatpak flatpak-builder
+        flatpak remote-add --if-not-exists --user flathub https://flathub.org/repo/flathub.flatpakrepo
+        flatpak install --user -y --noninteractive org.freedesktop.Platform//25.08 org.freedesktop.Sdk//25.08 org.electronjs.Electron2.BaseApp//25.08
 
     - name: Install Dependencies
       uses: nick-fields/retry@v3

README.md

@@ -112,6 +112,25 @@ Maybe you only want to execute the application in the browser with hot reload? J
 
 **Your application is optimised. Only /dist folder and NodeJS dependencies are included in the final bundle.**
 
+## Building Flatpak (Linux)
+
+On Linux, `npm run electron:build` produces both an AppImage and a Flatpak. The Flatpak build requires additional tooling:
+
+``` bash
+# Install flatpak and flatpak-builder
+sudo apt install flatpak flatpak-builder
+
+# Add the Flathub remote
+flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+
+# Install the required runtimes
+flatpak install flathub org.freedesktop.Platform//25.08
+flatpak install flathub org.freedesktop.Sdk//25.08
+flatpak install flathub org.electronjs.Electron2.BaseApp//25.08
+```
+
+Once the runtimes are installed, `npm run electron:build` will generate the Flatpak bundle alongside the AppImage in the `release/` folder.
+
 ## You want to use a specific lib (like rxjs) in electron main thread ?
 
 YES! You can do it! Just by importing your library in npm dependencies section of `app/package.json` with `npm install --save XXXXX`. \

electron-builder.json

@@ -32,7 +32,29 @@
   "linux": {
     "icon": "dist/browser/assets/icons",
     "target": [
-      "AppImage"
+      "AppImage",
+      {
+        "target": "flatpak",
+        "arch": ["x64"]
+      }
+    ]
+  },
+  "flatpak": {
+    "category": "Utility",
+    "base": "org.electronjs.Electron2.BaseApp",
+    "baseVersion": "25.08",
+    "runtime": "org.freedesktop.Platform",
+    "runtimeVersion": "25.08",
+    "sdk": "org.freedesktop.Sdk",
+    "finishArgs": [
+      "--socket=wayland",
+      "--socket=x11",
+      "--share=ipc",
+      "--device=dri",
+      "--socket=pulseaudio",
+      "--filesystem=home",
+      "--share=network",
+      "--talk-name=org.freedesktop.Notifications"
     ]
   }
 }