fix: Use Flathub as default remote for default-flatpaks

modules/default-flatpaks/README.md

@@ -2,6 +2,8 @@
 
 The `default-flatpaks` module removes the Fedora Flatpaks remote that comes pre-installed by Fedora, and can be used to install flatpaks from a configurable remote on first boot. Flatpaks can either be installed system-wide or per-user, though per-user flatpaks will be installed for every user on a system. Previously-installed flatpaks can also be removed.
 
+If no Flatpak remote is specified, the module will default to using Flathub.
+
 The module uses the following scripts to handle flatpak setup:
 
 - `/usr/bin/system-flatpak-setup`

modules/default-flatpaks/default-flatpaks.sh

@@ -23,6 +23,17 @@ configure_flatpak_repo () {
         repo_name=$(echo "$1" | yq -I=0 ".$2.repo-name")
         repo_title=$(echo "$1" | yq -I=0 ".$2.repo-title")
 
+        # Use Flathub as default repo
+        if [[ $repo_url == "null" ]]; then
+            repo_url=https://dl.flathub.org/repo/flathub.flatpakrepo
+        fi
+
+        # If repo-name isn't configured, use flathub as fallback
+        # Checked separately from URL to allow custom naming
+        if [[ $repo_name == "null" ]]; then
+            repo_name="flathub"
+        fi
+
         touch $repo_info
         # EOF breaks if the contents are indented,
         # so the below lines are intentionally un-indented