hosts in Go, with the machine's own name in its block (ADR 0199)

The tools were TypeScript; the mesh's modules are Go. The write to /etc/hosts is now staged and
moved into place rather than written over the live file.

modules/hosts/module.json

@@ -20,7 +20,7 @@
       "mode": "0644",
       "into": "block",
       "at": "start",
-      "content": "# The machine's own names (module hosts, novox/hq ADR 0199). Every line outside this block is the\n# operator's: kept across every push, changed through the node-hosts-file verbs add and remove, and\n# given back when this module goes. The mesh's names are not here: the mesh's resolver answers them.\n127.0.0.1\tlocalhost\n::1\tlocalhost\n"
+      "content": "# The machine's own names (module hosts, novox/hq ADR 0199). Every line outside this block is the\n# operator's: kept across every push, changed through the node-hosts-file verbs add and remove, and\n# given back when this module goes. The mesh's names are not here: the mesh's resolver answers them.\n127.0.0.1\tlocalhost\n::1\tlocalhost\n127.0.1.1\t${machine:name}\n"
     }
   ],
   "build": {
@@ -28,12 +28,12 @@
       {
         "name": "tools",
         "kind": "bundle",
-        "language": "typescript",
-        "entrypoints": [
-          "tools/index.js"
-        ],
+        "language": "go",
+        "system": "arch",
+        "from": "cmd/hosts-tools",
+        "binary": "hosts-tools",
         "loads": [
-          "tools/index.js"
+          "hosts-tools"
         ]
       }
     ]