Add Steam Deck (nix-deck) configuration with Jovian-NixOS and remote building

- Add Jovian-NixOS integration for Steam Deck hardware support
- Create nix-deck machine configuration with SteamOS role
- Add jovian-compat.nix for NixOS 25.05 compatibility (remove in 25.11+)
- Create remote-build role for distributed builds
- Configure zix790prors as build host
- Configure nix-book and nix-deck to use remote builder with fallback
- Add comprehensive setup documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

flake.lock

@@ -57,6 +57,27 @@
         "type": "github"
       }
     },
+    "jovian": {
+      "inputs": {
+        "nix-github-actions": "nix-github-actions",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1763223001,
+        "narHash": "sha256-Hi6XxTJJjKsDrO+D0fYXS88ehCYzQkZlp9qxX1zoM1s=",
+        "owner": "Jovian-Experiments",
+        "repo": "Jovian-NixOS",
+        "rev": "68a1bcc019378272e601558719f82005a80ddab0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Jovian-Experiments",
+        "repo": "Jovian-NixOS",
+        "type": "github"
+      }
+    },
     "nix-darwin": {
       "inputs": {
         "nixpkgs": [
@@ -78,6 +99,28 @@
         "type": "github"
       }
     },
+    "nix-github-actions": {
+      "inputs": {
+        "nixpkgs": [
+          "jovian",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1729697500,
+        "narHash": "sha256-VFTWrbzDlZyFHHb1AlKRiD/qqCJIripXKiCSFS8fAOY=",
+        "owner": "zhaofengli",
+        "repo": "nix-github-actions",
+        "rev": "e418aeb728b6aa5ca8c5c71974e7159c2df1d8cf",
+        "type": "github"
+      },
+      "original": {
+        "owner": "zhaofengli",
+        "ref": "matrix-name",
+        "repo": "nix-github-actions",
+        "type": "github"
+      }
+    },
     "nixos-wsl": {
       "inputs": {
         "flake-compat": "flake-compat",
@@ -173,6 +216,7 @@
       "inputs": {
         "google-cookie-retrieval": "google-cookie-retrieval",
         "home-manager": "home-manager",
+        "jovian": "jovian",
         "nix-darwin": "nix-darwin",
         "nixos-wsl": "nixos-wsl",
         "nixpkgs": "nixpkgs_2",