Fixed the Manager deployment database dependency.

Root cause
src/proxy.ts statically imported installation-state.ts, which statically imported Prisma. Additionally, the root layout statically imported business branding, which also loads Prisma. The pathname check was also incorrect for Manager deployments served at /.

src/proxy.ts

@@ -1,7 +1,6 @@
 import NextAuth from "next-auth";
-import { NextResponse } from "next/server";
+import { NextResponse, type NextRequest } from "next/server";
 import { authConfig } from "@/auth.config";
-import { isInstalledForRequest } from "@/lib/installation/installation-state";
 
 // /home, /appointments and /settings are intentionally NOT hard-gated here
 // as of Phase 4 — Home must work for guests (public business browsing +
@@ -21,7 +20,6 @@ const PROTECTED_PREFIXES = ["/staff", "/owner"];
 // business data guard themselves (see /api/health and
 // /api/cron/process-notifications).
 const INSTALL_EXEMPT_PREFIXES = [
-  "/manager",
   "/install",
   "/offline",
   "/manifest.webmanifest",
@@ -84,17 +82,23 @@ function buildCsp(): string {
   ].join("; ");
 }
 
-export default auth(async (req) => {
+export async function handleProxyRequest(req: NextRequest) {
   const { pathname } = req.nextUrl;
   const csp = buildCsp();
 
+  // Manager is a separate deployment and hostname, so its root pathname is
+  // normally `/`, not `/manager`. Branch before loading any business module.
+  if (process.env.MANAGER_MODE === "true") {
+    const response = NextResponse.next();
+    response.headers.set("Content-Security-Policy", csp);
+    return response;
+  }
+
   const isInstallExempt = INSTALL_EXEMPT_PREFIXES.some(
     (prefix) => pathname === prefix || pathname.startsWith(prefix.endsWith("/") ? prefix : `${prefix}/`),
   );
-  // The platform Manager is a separate deployment and deliberately has no
-  // business database. Its own session guard runs inside /manager pages/API.
-  const isManagerPath = pathname === "/manager" || pathname.startsWith("/manager/");
-  const installed = isManagerPath ? true : await isInstalledForRequest();
+  const { isInstalledForRequest } = await import("@/lib/installation/installation-state");
+  const installed = await isInstalledForRequest();
 
   if (!installed && !isInstallExempt) {
     const response = NextResponse.redirect(new URL("/install", req.nextUrl.origin));
@@ -126,7 +130,9 @@ export default auth(async (req) => {
   const response = NextResponse.next();
   response.headers.set("Content-Security-Policy", csp);
   return response;
-});
+}
+
+export default auth(handleProxyRequest);
 
 export const config = {
   matcher: ["/((?!api|_next/static|_next/image|favicon.ico).*)"],