fix: remove libcamera from pipewire buildInputs (both overlays)

meta.platforms = [] on libcamera doesn't help because nixos-25.11 pipewire
has libcamera unconditionally in buildInputs. Must overrideAttrs to:
- filter libcamera out of buildInputs
- clear existing libcamera meson flags and set -Dlibcamera=disabled

flake.nix

@@ -101,9 +101,20 @@
               boot.loader.raspberry-pi.bootloader = "kernel";
               # Kill camera packages — not needed on uConsole, break cross-compile
               nixpkgs.overlays = [
+                # Make camera packages "unavailable" so no pkgs depend on them
                 (final: prev: {
+                  libcamera = prev.libcamera.overrideAttrs (_: { meta.platforms = []; });
+                  libcamera-rpi = prev.libcamera-rpi.overrideAttrs (_: { meta.platforms = []; });
+                  libpisp = prev.libpisp.overrideAttrs (_: { meta.platforms = []; });
+                  # Pipewire in nixos-25.11 has libcamera unconditionally in buildInputs;
+                  # meta.platforms trick doesn't help — must actually remove it
                   pipewire = prev.pipewire.overrideAttrs (old: {
-                    mesonFlags = old.mesonFlags ++ [ "-Dlibcamera=disabled" ];
+                    buildInputs = builtins.filter
+                      (x: !(x?pname && x.pname == "libcamera"))
+                      (old.buildInputs or []);
+                    mesonFlags = builtins.filter
+                      (flag: !(builtins.isString flag && builtins.match ".*libcamera.*" flag != null))
+                      (old.mesonFlags or []) ++ [ "-Dlibcamera=disabled" ];
                   });
                 })
               ];
@@ -114,7 +125,12 @@
               nixpkgs.overlays = [
                 (final: prev: {
                   pipewire = prev.pipewire.overrideAttrs (old: {
-                    mesonFlags = old.mesonFlags ++ [ "-Dlibcamera=disabled" ];
+                    buildInputs = builtins.filter
+                      (x: !(x?pname && x.pname == "libcamera"))
+                      (old.buildInputs or []);
+                    mesonFlags = builtins.filter
+                      (flag: !(builtins.isString flag && builtins.match ".*libcamera.*" flag != null))
+                      (old.mesonFlags or []) ++ [ "-Dlibcamera=disabled" ];
                   });
                 })
               ];