initial NextChair Manager.

Key additions:
* Separate platform Manager stack: [stacks/manager/compose.yaml]
* Dedicated manager authentication with signed sessions.
* Business overview dashboard.
* Add Business workflow with slug suggestions and deployment progress.
* Business detail page with start, stop, restart, update, logs, Dockge, and conservative removal actions.
* Explicit management API endpoints under [src/app/api/manager]
* Shared provisioning service layer in [provisioning.service.ts]
* CLI and UI now use the same [create-business.sh] provisioning logic.
* Registry metadata, database status, container health, and media usage reporting.
* Manager-only entrypoint mode that does not require a business database.
* Updated deployment documentation with Manager setup and Caddy routing.
Validation passed:
* Infra, Caddy, Manager, and generated business Compose configurations.
* Shell syntax checks.
* Registry generation with registry image tags.
* git diff --check.

src/app/api/manager/businesses/route.ts

@@ -0,0 +1,25 @@
+import { NextResponse } from "next/server";
+import { isManagerAuthenticated } from "@/services/management/management-auth";
+import { createBusiness, listBusinesses } from "@/services/management/provisioning.service";
+
+export async function GET() {
+  if (!(await isManagerAuthenticated())) return NextResponse.json({ error: "Unauthorized." }, { status: 401 });
+  return NextResponse.json(await listBusinesses());
+}
+
+export async function POST(request: Request) {
+  if (!(await isManagerAuthenticated())) return NextResponse.json({ error: "Unauthorized." }, { status: 401 });
+  const body = (await request.json().catch(() => null)) as Record<string, unknown> | null;
+  const name = typeof body?.name === "string" ? body.name.trim() : "";
+  const slug = typeof body?.slug === "string" ? body.slug.trim().toLowerCase() : "";
+  const domain = typeof body?.domain === "string" ? body.domain.trim().toLowerCase() : "";
+  const image = typeof body?.image === "string" ? body.image.trim() : "";
+  if (!name || name.length > 120 || !/^[a-z0-9]+(?:-[a-z0-9]+)*$/.test(slug) || slug.length > 22 || !/^[a-z0-9.-]+$/.test(domain) || !/^[A-Za-z0-9._/@:-]+$/.test(image)) {
+    return NextResponse.json({ error: "Enter a valid business name, slug, domain, and image version." }, { status: 400 });
+  }
+  try {
+    return NextResponse.json(await createBusiness({ name, slug, domain, image }), { status: 201 });
+  } catch (error) {
+    return NextResponse.json({ error: error instanceof Error ? error.message : "Business deployment failed." }, { status: 500 });
+  }
+}