chore(nix): bump nixpkgs 24.05 → 24.11

Three breakages handled:

- hardware.opengl → hardware.graphics (renamed in 24.11). Touches
  upboard.nix, douro.nix, batm3.nix, live.nix.
- vaapiIntel dropped — legacy pre-Broadwell driver, removed in
  nixpkgs. UP Board (Cherry Trail) and OptiPlex 9030 (Haswell) both
  use intel-media-driver, which stays.
- vaapiVdpau renamed → libva-vdpau-driver.

system.stateVersion stays 24.05 — convention is to never bump after
install. Existing Sintra and fresh flashes keep the 24.05 state
semantics; that's correct.

All 8 nixosConfigurations (4 models × {live,installed}) evaluate
clean with zero deprecation warnings on 24.11.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

deploy/nixos/live.nix

@@ -109,14 +109,12 @@ in
   };
 
   # Intel GPU support
-  # NB: nixos-24.05 uses hardware.opengl, not hardware.graphics
   hardware = {
-    opengl = {
+    graphics = {
       enable = true;
       extraPackages = with pkgs; [
         intel-media-driver
-        vaapiIntel
-        vaapiVdpau
+        libva-vdpau-driver
         libvdpau-va-gl
       ];
     };