turny: fix SPI/GPIO config for newer kernels

- Add complete config.txt settings with u-boot boot lines + spi=on
- Override sdImage.populateFirmwareCommands to use configtxt module output
- Mount firmware partition and add activation script to sync config.txt
- Load spi_bcm2835 and bcm2835_gpiomem kernel modules
- Add udev rule for gpiomem subsystem (not just gpio)
- Relax ProtectKernelTunables so service can access GPIO
- Update turny flake input to rppal-based CS pin fix

hosts/radish/containers.nix

@@ -13,7 +13,6 @@
       enable = true;
       autoPrune.enable = true;
       defaultNetwork.settings.dns_enabled = true;
-      package = pkgs-unstable.podman;
       dockerCompat = true;
     };
   };

hosts/radish/desktop.nix

@@ -1,4 +1,4 @@
-{ pkgs-unstable, ... }:
+{ lib, pkgs-unstable, ... }:
 {
   services.displayManager.gdm.enable = true;
   services.desktopManager.gnome.enable = true;
@@ -24,7 +24,7 @@
   services.pipewire = {
     enable = true;
     alsa.enable = true;
-    alsa.support32Bit = true;
+    alsa.support32Bit = lib.mkForce false;
     pulse.enable = true;
     jack.enable = true;
   };