Add declarative Flatpak support via nix-flatpak

Integrates the nix-flatpak module for declarative Flatpak management. Enables Flatpak system-wide, configures Home Manager to manage Flatpak apps, and adds an example Flatpak package with automatic weekly updates.

flake.nix

@@ -10,6 +10,9 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
     
+    # Declarative Flatpak management
+    nix-flatpak.url = "github:gmodena/nix-flatpak";
+    
     # Optional: Hyprland (if you want a tiling Wayland compositor)
     # hyprland.url = "github:hyprwm/Hyprland";
     
@@ -17,7 +20,7 @@
     # nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = { self, nixpkgs, home-manager, ... }@inputs: {
+  outputs = { self, nixpkgs, home-manager, nix-flatpak, ... }@inputs: {
     # NixOS configuration for your hostname(s)
     nixosConfigurations = {
       # Desktop PC configuration
@@ -43,6 +46,9 @@
             
             # User configuration
             home-manager.users.zeph = import ./home/home.nix;
+            
+            # Declarative Flatpak
+            home-manager.sharedModules = [ nix-flatpak.homeManagerModules.nix-flatpak ];
           }
         ];
       };
@@ -70,6 +76,9 @@
             
             # User configuration
             home-manager.users.zeph = import ./home/home.nix;
+            
+            # Declarative Flatpak
+            home-manager.sharedModules = [ nix-flatpak.homeManagerModules.nix-flatpak ];
           }
         ];
       };

home/home.nix

@@ -154,6 +154,18 @@
   #   platformTheme.name = "gtk";
   # };
 
+  # Declarative Flatpak packages
+  services.flatpak = {
+    packages = [
+      "io.github.zen_browser.zen"
+      # Add more Flatpak apps here
+    ];
+    update.auto = {
+      enable = true;
+      onCalendar = "weekly";
+    };
+  };
+
   # Let Home Manager manage itself
   programs.home-manager.enable = true;
 

system/common.nix

@@ -10,6 +10,9 @@
   # Networking
   networking.networkmanager.enable = true;
 
+  # Enable Flatpak
+  services.flatpak.enable = true;
+
   # Timezone and locale
   time.timeZone = "Europe/London";
   i18n.defaultLocale = "en_US.UTF-8";