Grant network access so update checks can reach GitHub (#2413)

Add --share=network to the finish-args of both Flatpak manifests. Without it
the sandbox cannot resolve or reach GitHub, so update checks fail with
"Temporary failure in name resolution". The two manifests keep identical
finish-args.

packaging/linux/flatpak/ai.storyteller.cadcraft.bundle.yml

@@ -24,15 +24,15 @@ finish-args:
   - --share=ipc
   # GPU access for the wgpu canvas (Vulkan, or GL as a fallback).
   - --device=dri
+  # Outbound network access (HTTPS).
+  - --share=network
   # Open/Save dialogs go through the file-chooser portal (rfd) and drag-and-drop through the
   # document portal, so picked files work anywhere without broad filesystem access. Documents
   # and Pictures are granted so drawings passed by path (the command line, Open Recent, xrefs
   # and images next to a DXF) work in the usual places.
   - --filesystem=xdg-documents
   - --filesystem=xdg-pictures
-  # Deliberately not granted: network (the optional --control server listens on 127.0.0.1 in
-  # the sandbox; `flatpak override --user --share=network ai.storyteller.cadcraft` exposes it to
-  # host agents) and home/host filesystem access.
+  # Deliberately not granted: home/host filesystem access.
 modules:
   - name: cadcraft
     buildsystem: simple

packaging/linux/flatpak/ai.storyteller.cadcraft.yml

@@ -25,15 +25,15 @@ finish-args:
   - --share=ipc
   # GPU access for the wgpu canvas (Vulkan, or GL as a fallback).
   - --device=dri
+  # Outbound network access (HTTPS).
+  - --share=network
   # Open/Save dialogs go through the file-chooser portal (rfd) and drag-and-drop through the
   # document portal, so picked files work anywhere without broad filesystem access. Documents
   # and Pictures are granted so drawings passed by path (the command line, Open Recent, xrefs
   # and images next to a DXF) work in the usual places.
   - --filesystem=xdg-documents
   - --filesystem=xdg-pictures
-  # Deliberately not granted: network (the optional --control server listens on 127.0.0.1 in
-  # the sandbox; `flatpak override --user --share=network ai.storyteller.cadcraft` exposes it to
-  # host agents) and home/host filesystem access.
+  # Deliberately not granted: home/host filesystem access.
 build-options:
   append-path: /usr/lib/sdk/rust-stable/bin
 modules: