feat: per-server nixpkgs pins (all follow default)

flake.lock

@@ -18,7 +18,22 @@
     },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-armer": [
+          "nixpkgs"
+        ],
+        "nixpkgs-bim": [
+          "nixpkgs"
+        ],
+        "nixpkgs-howard": [
+          "nixpkgs"
+        ],
+        "nixpkgs-mermaid": [
+          "nixpkgs"
+        ],
+        "nixpkgs-micron": [
+          "nixpkgs"
+        ]
       }
     }
   },

flake.nix

@@ -1,7 +1,17 @@
 {
-  description = "Shared nixpkgs pin for the server fleet";
+  description = "Shared nixpkgs pins for the server fleet";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/2fc6539b481e1d2569f25f8799236694180c0993";
+  inputs = {
+    # Default pin — all servers follow this unless overridden below
+    nixpkgs.url = "github:NixOS/nixpkgs/2fc6539b481e1d2569f25f8799236694180c0993";
 
-  outputs = { self, nixpkgs }: { };
+    # Per-server pins (follow default; replace with a direct url to override)
+    nixpkgs-armer.follows = "nixpkgs";
+    nixpkgs-bim.follows = "nixpkgs";
+    nixpkgs-howard.follows = "nixpkgs";
+    nixpkgs-mermaid.follows = "nixpkgs";
+    nixpkgs-micron.follows = "nixpkgs";
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-armer, nixpkgs-bim, nixpkgs-howard, nixpkgs-mermaid, nixpkgs-micron }: { };
 }