Fix proton-vpn rename on Gaming, restore zramSwap

The 25.11 channel renamed proton-vpn to protonvpn-gui; Macbook was
patched in an earlier commit but Gaming wasn't, breaking the build.

zramSwap goes back into common.nix as the cheap OOM-during-uncached-build
safety net — even on stable, --refresh against a freshly-bumped lock can
trigger local builds the box has no swap to absorb.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

common.nix

@@ -59,6 +59,14 @@
   boot.initrd.verbose = false;
 #############################################################################
 
+  # Compressed in-memory swap as a safety net during local build storms.
+  # Cheap when idle; without it a transient OOM during an uncached build
+  # can stall AdGuard/Jellyfin to the point of freezing the box.
+  zramSwap = {
+    enable = true;
+    memoryPercent = 50;
+  };
+
   # Use latest kernel
   boot.kernelPackages = pkgs.linuxPackages_latest;