chore(template): clean-slate template snapshot from bb4a0c7

Curated, product-agnostic snapshot of the post-story-04 tree: demo
content deleted, auth-only reference feature, web-next shell, all gates
green. Product-specific docs, ADRs 027-029, PRDs/epics/archive, editor
library traces, and product naming are curated out; generic template
repairs (coverage provider devDeps, root test:coverage script, live
lint fixes, root-only release-please) are kept. See TEMPLATE.md for
provenance, curation list, and usage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

packages/core-dsr/src/handlers/restrict-handler.ts

@@ -0,0 +1,18 @@
+import type { IProcessingRestriction } from "../processing-restriction.interface";
+import type { HandlerResponse } from "./handler-types";
+
+export type RestrictHandlerInput = {
+  subjectId: string;
+  granted: boolean;
+};
+
+export function createRestrictHandler(
+  processingRestriction: IProcessingRestriction,
+) {
+  return async (
+    input: RestrictHandlerInput,
+  ): Promise<HandlerResponse<{ ok: true }>> => {
+    await processingRestriction.setRestriction(input.subjectId, input.granted);
+    return { status: 200, body: { ok: true as const } };
+  };
+}