fix: resolve JSR slow-type error and annotate unanalyzable dynamic import

- Add explicit return type to WithDsdHydration mixin (missing-explicit-return-type)
- New DsdHydrationMixin interface for public API type contract
- Document intentional dynamic import in scanPackageIslands (unanalyzable-dynamic-import warning)

Author: SisyphusZheng

packages/adapter-lit/src/dsd-hydration.ts

@@ -60,6 +60,20 @@ export interface DsdHydration {
   _hydrateEvents(): void;
 }
 
+/**
+ * Instance interface added by the WithDsdHydration mixin beyond DsdHydration.
+ * Captures the LitElement method overrides the mixin provides.
+ * Required by JSR slow-types checker for explicit public API return types.
+ */
+export interface DsdHydrationMixin extends DsdHydration {
+  /** Override: reuses existing shadow root when DSD-pre-populated */
+  createRenderRoot(): HTMLElement | DocumentFragment;
+  /** Override: auto-wires DSD hydration events on connect */
+  connectedCallback(): void;
+  /** Override: cleans up hydration listeners on disconnect */
+  disconnectedCallback(): void;
+}
+
 /**
  * Mixin that adds DSD hydration support to a LitElement subclass.
  *
@@ -73,7 +87,9 @@ export interface DsdHydration {
  * - Declare `static hydrateEvents: HydrateEventDescriptor[]`
  * - Check `if (this._dsdHydrated) return nothing` at the top of render()
  */
-export function WithDsdHydration<T extends Constructor<LitElement>>(superClass: T) {
+export function WithDsdHydration<T extends Constructor<LitElement>>(
+  superClass: T,
+): T & Constructor<DsdHydrationMixin> {
   class WithDsdHydrationClass extends superClass {
     /**
      * Declarative event bindings for DSD hydration.
@@ -168,7 +184,7 @@ export function WithDsdHydration<T extends Constructor<LitElement>>(superClass:
     }
   }
 
-  return WithDsdHydrationClass as unknown as T & Constructor<WithDsdHydrationClass>;
+  return WithDsdHydrationClass as unknown as T & Constructor<DsdHydrationMixin>;
 }
 
 /**

packages/adapter-lit/src/index.ts

@@ -24,4 +24,4 @@
 export { installLitAdapter, uninstallLitAdapter } from './ssr.js';
 export { isLitTemplateResult, renderLitToString } from './ssr.js';
 export { DsdLitElement, WithDsdHydration } from './dsd-hydration.js';
-export type { DsdHydration } from './dsd-hydration.js';
+export type { DsdHydration, DsdHydrationMixin } from './dsd-hydration.js';

packages/core/src/route-scanner.ts

@@ -255,7 +255,12 @@ export async function scanPackageIslands(
 
   for (const pkg of packageNames) {
     try {
-      // Dynamic import the package
+      // JSR publishes a warning[unanalyzable-dynamic-import] here because
+      // `pkg` is a variable — JSR cannot resolve it at publish time.
+      // This is intentional: packageNames are user-configured (e.g. ['@lessjs/ui'])
+      // and must resolve at runtime via the consumer's import map / package.json.
+      // The warning does NOT block publishing; the import resolves correctly
+      // in the consuming project where the target package is a declared dependency.
       const mod = await import(pkg);
       if (mod.islands && Array.isArray(mod.islands)) {
         // Validate each island has required fields