feat: collapse plugin runtime to one tier behind a plugin SDK

packages/plugin-sdk/src/frontend.ts

@@ -0,0 +1,40 @@
+/**
+ * The frontend contract: what a plugin's frontend entry receives.
+ *
+ * Stubs only. A7 builds the real loader and fills these in, at which point a
+ * plugin registers every surface it contributes through this object and the
+ * shell stops carrying plugin ids of its own.
+ */
+
+import type { PluginManifest } from "./manifest.js";
+
+export interface TermixAppInfo {
+  readonly pluginId: string;
+  readonly manifest: PluginManifest;
+}
+
+/**
+ * Registration surface for a plugin frontend.
+ *
+ * A7 adds: rail items, panels, tabs, host editor sections, host actions and
+ * badges, context menu items, palette entries, dashboard cards, homepage
+ * widgets, settings components, action slots, login/2FA UI and SSH auth
+ * editors. Everything registered here is removed when the plugin is disabled.
+ */
+export interface TermixApp extends TermixAppInfo {
+  /** Registered cleanup, run when the plugin is disabled. */
+  onDispose: (dispose: () => void) => void;
+}
+
+export type FrontendActivate = (app: TermixApp) => void | Promise<void>;
+
+export interface FrontendModule {
+  activate: FrontendActivate;
+  deactivate?: () => void | Promise<void>;
+}
+
+export function definePluginFrontend(plugin: FrontendModule): FrontendModule {
+  return plugin;
+}
+
+export type { PluginManifest } from "./manifest.js";