feat(dev): add gastown multi-agent workspace manager

- Add gastown flake input (non-flake, source only)
- Build gastown package using buildGoModule in development role
- Configure renovate for daily updates of gastown and beads
- Binary: gt (Gas Town CLI by Steve Yegge)

renovate.json

@@ -59,6 +59,32 @@
       "matchPackageNames": [
         "/google-cookie-retrieval/"
       ]
+    },
+    {
+      "description": "Gastown is under active development - check for updates daily",
+      "matchManagers": [
+        "nix"
+      ],
+      "matchPackageNames": [
+        "/gastown/"
+      ],
+      "schedule": [
+        "before 6am every day"
+      ],
+      "automerge": false
+    },
+    {
+      "description": "Beads is under active development - check for updates daily",
+      "matchManagers": [
+        "nix"
+      ],
+      "matchPackageNames": [
+        "/beads/"
+      ],
+      "schedule": [
+        "before 6am every day"
+      ],
+      "automerge": false
     }
   ]
 }