feat: add host sections, tab embeds and the operations client to the plugin ui

src/ui/shell/host-sections.ts

@@ -0,0 +1,43 @@
+import type { ComponentType } from "react";
+import type { Host } from "@/types/ui-types";
+import { byOrderThenId, createRegistry } from "@/lib/registry";
+import type { TabShellCallbacks } from "@/shell/tab-registry";
+
+export interface HostSectionRenderProps {
+  host: Host;
+  isVisible: boolean;
+  shell: TabShellCallbacks;
+}
+
+/**
+ * A card a plugin adds to a host page. The page itself belongs to a plugin;
+ * core only keeps the list so any plugin can fill it.
+ */
+export interface HostSectionDef {
+  id: string;
+  pluginId?: string;
+  titleKey: string;
+  order?: number;
+  when: (host: Host) => boolean;
+  component: ComponentType<HostSectionRenderProps>;
+}
+
+const sections = createRegistry<HostSectionDef>(byOrderThenId);
+
+export const registerHostSection = sections.register;
+export const useHostSections = sections.useList;
+export const listHostSections = sections.list;
+export const resetHostSections = sections.reset;
+
+export function hostSectionsFor(
+  all: HostSectionDef[],
+  host: Host,
+): HostSectionDef[] {
+  return all.filter((section) => {
+    try {
+      return section.when(host);
+    } catch {
+      return false;
+    }
+  });
+}