refactor: thread agent packages via option, drop overlay and forge-tools shim

nix/templates/harness/forge.nix

@@ -45,8 +45,9 @@ in
       # claude can `tea repos create`, `tea pulls create`, etc.
       pkgs.tea
       # hive-forge <verb>: CLI wrapping common Forgejo REST API operations
-      # (view, pr, issue, comment, assign, close, labels, branches, etc.)
-      (pkgs.callPackage ../../packages/hive-forge-tools.nix { })
+      # (view, pr, issue, comment, assign, close, labels, branches, etc.).
+      # The per-bin split package — narrow closure, no hivectl/wireguard.
+      config.hyperhive.packages.hive-forge
     ];
 
     # One-shot: tea config.yml from the seeded forge token. Shape