feat(orchestrator): W3 artifacts tree, ancestry, gates and token-free cleanup

Artifacts show the branch tree with ancestry and gate marks. The cleanup runner calls pkgmgr branch cleanup with its real argv and parses its repos[*].items output, refuses any plan with a remote-branch action, marks an item done only when pkgmgr reports it done, and offers no delete for a branch a worktree holds. Every text states what the pkgmgr command does to volumes. Committed below the bar on the operator's word 2026-11-12 (no further per-bundle tests, one gate after the merge): the W3 e2e never ran; the client switches to --local once pkgmgr ships it.

🎯 Fix: 90 %
💥 Break: 6 %
💸 Cost: 30 %
⏱️ Time: 40 %
🛡️ Security: 100 %
🏆 Score: 100
🚦 Gate: ⛔ break 6 % > 5

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

orchestrator/templates/page-spawn.js

@@ -117,5 +117,6 @@
     const running = all.filter((entry) => entry.running).length;
     spawn.dom.list.replaceChildren(
       h("div", {class: "inbox-head"}, h("h2", {class: "group-title"}, "Spawn tree", counter(all.length)), h("span", {class: "muted"}, `${running} running · ${all.length - running} finished · Operator → Chair → Sessions → Subagents`)),
+      agentAncestry(root),
       h("ul", {class: "spawn-tree root"}, spawnItem(root)));
   }