feat(uconsole): add cm5 cross-compiled nixosConfiguration

- New host: uconsole-cm5 (aarch64-linux, cross-built from x86_64)
- SSH authorizedKeys: gortium.main + ai-worker.main
- NetworkManager enabled (WiFi password via agenix later)
- Display: vc4/panel_cwu50/rp1_dsi with empty initrd
- Config.txt [pi5] section (not [cm5])
- Backlight fix service
- nixos-raspberrypi → gortium/cm5-cross-v1 fork (PR #197)
- nixpkgs-uconsole pinned to nixos-25.11 (kernel patch compat)

V3 branch saved as archive/uconsole-cm5-v3 (Reticulum/SDR/HAM config).

flake.nix

@@ -12,10 +12,23 @@
       url = "git+https://git.lix.systems/lix-project/lix?ref=main";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    # uConsole CM5 — pinned nixpkgs for kernel patch compatibility
+    nixpkgs-uconsole.url = "github:NixOS/nixpkgs/nixos-25.11";
+    nixos-uconsole = {
+      url = "github:nixos-uconsole/nixos-uconsole/v1.1.0";
+      inputs.nixpkgs.follows = "nixpkgs-uconsole";
+    };
+    nixos-raspberrypi = {
+      url = "github:gortium/nixos-raspberrypi/cm5-cross-v1";
+      inputs.nixpkgs.follows = "nixpkgs-uconsole";
+    };
     self.submodules = true;
   };
 
-  outputs = { self, nixpkgs, agenix, lix, ... }@inputs:
+  outputs = { self, nixpkgs, agenix, lix
+            , nixpkgs-uconsole, nixos-uconsole, nixos-raspberrypi
+            , ... }@inputs:
     let
       system = "x86_64-linux";
       keys = import ./lib/keys.nix;
@@ -80,6 +93,48 @@
               ./hosts/cyt-pi/hardware-configuration.nix
             ];
           };
+
+          # ============================================================
+          # uConsole CM5 — cross-compilé (build sur x86_64, run sur ARM)
+          # Approche incrémentale pour fixer l'écran
+          # ============================================================
+          uconsole-cm5 = nixpkgs-uconsole.lib.nixosSystem {
+            system = "aarch64-linux";
+            specialArgs = {
+              inherit self keys paths inputs;
+              nixos-raspberrypi = nixos-raspberrypi;
+              isCM4 = false;
+            };
+            modules = [
+              {
+                # Cross-compile : build sur x86_64, run sur aarch64
+                nixpkgs.buildPlatform = "x86_64-linux";
+                nixpkgs.hostPlatform = "aarch64-linux";
+                nixpkgs.config.allowUnfree = true;
+                boot.loader.raspberry-pi.bootloader = "kernel";
+              }
+              # nixos-raspberrypi — crée pkgs.rpi avec kernel/firmware cross-compilés
+              nixos-raspberrypi.nixosModules.nixpkgs-rpi
+              {
+                nixpkgs.overlays = [
+                  nixos-raspberrypi.overlays.bootloader
+                  nixos-raspberrypi.overlays.vendor-kernel
+                  nixos-raspberrypi.overlays.vendor-firmware
+                  nixos-raspberrypi.overlays.kernel-and-firmware
+                  nixos-raspberrypi.overlays.vendor-pkgs
+                  nixos-raspberrypi.overlays.pkgs
+                ];
+              }
+              # nixos-uconsole CM5 modules
+              nixos-uconsole.nixosModules.kernel
+              nixos-uconsole.nixosModules.configtxt
+              (nixos-uconsole.nixosModules.cm { lib = nixpkgs-uconsole.lib; isCM4 = false; })
+              nixos-uconsole.nixosModules.base
+              # Notre config
+              ./hosts/uconsole-cm5/configuration.nix
+              ./hosts/uconsole-cm5/hardware-configuration.nix
+            ];
+          };
         };
         devShells.${system}.default = devShell;
       };