fix: host defaults tabs sit where the host editor puts them and skip plugins with nothing to default

src/ui/settings/host-feature-tabs.tsx

@@ -12,12 +12,13 @@ import {
   registerHostEditorSection,
   unregisterHostEditorSection,
 } from "@/sidebar/HostManagerTabs";
-import type { PluginSummary } from "@/api/plugins-api";
+import type { PluginSettingsField, PluginSummary } from "@/api/plugins-api";
 import {
   HostPluginSections,
   type HostPluginSettings,
 } from "./HostPluginSections";
 import { hasVisibleFields } from "./settings-fields-util";
+import { isDefaultableField } from "@/sidebar/host-defaults/catalog";
 
 const TAB_PREFIX = "feature:";
 
@@ -29,6 +30,16 @@ interface HostFormLike {
   pluginSettings?: HostPluginSettings;
 }
 
+function hasDefaultableFields(host: {
+  enableKey?: string;
+  fields: PluginSettingsField[];
+}): boolean {
+  return (
+    !!host.enableKey ||
+    host.fields.some((field) => !field.hidden && isDefaultableField(field))
+  );
+}
+
 /** Adds, updates and removes generated tabs to match the plugin list. */
 export function syncHostFeatureTabs(plugins: PluginSummary[]): string[] {
   const existing = hostEditorSectionList();
@@ -36,6 +47,19 @@ export function syncHostFeatureTabs(plugins: PluginSummary[]): string[] {
     (section) => section.pluginId && !section.id.startsWith(TAB_PREFIX),
   );
   const ownSections = new Set(own.map((section) => section.pluginId));
+  // The defaults tab sits where the plugin's own section does on a host.
+  const ownPlacement = new Map<
+    string,
+    { group: "top" | "ssh"; order?: number }
+  >();
+  for (const section of own) {
+    if (!ownPlacement.has(section.pluginId!)) {
+      ownPlacement.set(section.pluginId!, {
+        group: section.group,
+        order: section.order,
+      });
+    }
+  }
   // A plugin whose own sections are all about one host still gets its
   // switches in the defaults editor, through a generated tab shown only there.
   const ownDefaultsSections = new Set(
@@ -47,7 +71,10 @@ export function syncHostFeatureTabs(plugins: PluginSummary[]): string[] {
   const contributors = plugins.filter((plugin) => {
     if (!plugin.enabled || ownDefaultsSections.has(plugin.id)) return false;
     const host = plugin.contributes?.settings?.host;
-    return !!host && (hasVisibleFields(host.fields) || !!host.enableKey);
+    if (!host) return false;
+    // Its own section edits it per host, so only a default is left to offer.
+    if (ownSections.has(plugin.id)) return hasDefaultableFields(host);
+    return hasVisibleFields(host.fields) || !!host.enableKey;
   });
 
   const wanted = new Set(
@@ -62,11 +89,12 @@ export function syncHostFeatureTabs(plugins: PluginSummary[]): string[] {
   for (const plugin of contributors) {
     const host = plugin.contributes!.settings!.host!;
     const icon = plugin.icon;
+    const placement = ownPlacement.get(plugin.id);
     registerHostEditorSection({
       id: hostFeatureTabId(plugin.id),
       pluginId: plugin.id,
-      group: host.editorGroup ?? "top",
-      order: host.editorOrder ?? 100,
+      group: placement?.group ?? host.editorGroup ?? "top",
+      order: placement?.order ?? host.editorOrder ?? 100,
       labelKey: plugin.name,
       label: plugin.name,
       // Nothing but the plugin's host settings, so it works for defaults too.

src/ui/tests/settings/host-feature-tabs.test.tsx

@@ -121,6 +121,51 @@ describe("syncHostFeatureTabs", () => {
     );
   });
 
+  it("places the defaults tab where the plugin's own section sits", () => {
+    registerHostEditorSection({
+      id: "docker-own",
+      pluginId: "docker",
+      group: "ssh",
+      order: 40,
+      labelKey: "k",
+      component: () => null,
+    });
+    syncHostFeatureTabs([plugin()]);
+    const tab = getHostEditorSection(hostFeatureTabId("docker"));
+    expect(tab?.group).toBe("ssh");
+    expect(tab?.order).toBe(40);
+  });
+
+  it("gives a plugin with its own section no tab when nothing can have a default", () => {
+    registerHostEditorSection({
+      id: "proxmox-own",
+      pluginId: "proxmox",
+      group: "ssh",
+      labelKey: "k",
+      component: () => null,
+    });
+    const proxmox = plugin({
+      id: "proxmox",
+      name: "Proxmox",
+      contributes: {
+        settings: {
+          host: {
+            fields: [
+              {
+                key: "enableProxmox",
+                type: "custom",
+                component: "proxmoxHostSettings",
+                defaultable: false,
+              },
+            ],
+          },
+        },
+      },
+    } as Partial<PluginSummary>);
+    expect(syncHostFeatureTabs([proxmox])).toEqual([]);
+    expect(getHostEditorSection(hostFeatureTabId("proxmox"))).toBeUndefined();
+  });
+
   it("skips a plugin whose own section already covers the defaults editor", () => {
     registerHostEditorSection({
       id: "docker-own",