hub resource limits (#900)

- Feature: Hub dashboard now shows a Resources tile with disk and memory usage against configured limits
- Feature: Hub module listing now shows state-change timestamps and duration for each instance
- Improvement: Hub provisioning rejects new instances when disk or memory usage exceeds configurable thresholds; limits are disabled by default (0 = no limit)
  - `--hub-provision-disk-limit-bytes` - Reject provisioning when used disk exceeds this many bytes
  - `--hub-provision-disk-limit-percent` - Reject provisioning when used disk exceeds this percentage of total disk
  - `--hub-provision-memory-limit-bytes` - Reject provisioning when used memory exceeds this many bytes
  - `--hub-provision-memory-limit-percent` - Reject provisioning when used memory exceeds this percentage of total RAM
- Improvement: Hub process metrics are now tracked atomically per active instance slot, eliminating per-query process handle lookups
- Improvement: Hub, Build Store, and Workspaces service stats sections in the dashboard are now collapsible
- Bugfix: Hub watchdog loop did not check `m_ShutdownFlag`, causing it to spin indefinitely on shutdown

1 files changed, 0 insertions, 33 deletions

diff --git a/src/zenserver/frontend/html/pages/cache.js b/src/zenserver/frontend/html/pages/cache.js
index 1fc8227c8..e0f6f73b6 100644
--- a/src/zenserver/frontend/html/pages/cache.js
+++ b/src/zenserver/frontend/html/pages/cache.js
@@ -95,39 +95,6 @@ export class Page extends ZenPage
 		}
 	}
 
-	_collapsible_section(name)
-	{
-		const section = this.add_section(name);
-		const container = section._parent.inner();
-		const heading = container.firstElementChild;
-
-		heading.style.cursor = "pointer";
-		heading.style.userSelect = "none";
-
-		const indicator = document.createElement("span");
-		indicator.textContent = " \u25BC";
-		indicator.style.fontSize = "0.7em";
-		heading.appendChild(indicator);
-
-		let collapsed = false;
-		heading.addEventListener("click", (e) => {
-			if (e.target !== heading && e.target !== indicator)
-			{
-				return;
-			}
-			collapsed = !collapsed;
-			indicator.textContent = collapsed ? " \u25B6" : " \u25BC";
-			let sibling = heading.nextElementSibling;
-			while (sibling)
-			{
-				sibling.style.display = collapsed ? "none" : "";
-				sibling = sibling.nextElementSibling;
-			}
-		});
-
-		return section;
-	}
-
 	_render_stats(stats)
 	{
 		const safe = (obj, path) => path.split(".").reduce((a, b) => a && a[b], obj);