diff --git a/src/__tests__/proxy-manager-mode.test.ts b/src/__tests__/proxy-manager-mode.test.ts
deleted file mode 100644
index dbe8e5e..0000000
--- a/src/__tests__/proxy-manager-mode.test.ts
+++ /dev/null
@@ -1,59 +0,0 @@
-import { afterEach, describe, expect, it, vi } from "vitest";
-import { NextRequest } from "next/server";
-
-const isInstalledForRequest = vi.fn();
-
-// If proxy.ts or its Manager request path statically imports Prisma, this
-// mock throws while the test module is loading. Manager mode must not reach it.
-vi.mock("@/lib/db/prisma", () => {
-  throw new Error("Prisma must not be imported by the Manager proxy path.");
-});
-
-vi.mock("@/lib/installation/installation-state", () => ({ isInstalledForRequest }));
-
-import { handleProxyRequest } from "@/proxy";
-
-function request(pathname: string) {
-  return new NextRequest(`https://manager.example.com${pathname}`);
-}
-
-describe("proxy deployment separation", () => {
-  const originalManagerMode = process.env.MANAGER_MODE;
-
-  afterEach(() => {
-    if (originalManagerMode === undefined) delete process.env.MANAGER_MODE;
-    else process.env.MANAGER_MODE = originalManagerMode;
-    isInstalledForRequest.mockReset();
-  });
-
-  it("serves the Manager root without loading or checking business installation state", async () => {
-    process.env.MANAGER_MODE = "true";
-
-    const response = await handleProxyRequest(request("/"));
-
-    expect(response.status).toBe(200);
-    expect(response.headers.get("content-security-policy")).toContain("default-src 'self'");
-    expect(isInstalledForRequest).not.toHaveBeenCalled();
-  });
-
-  it("checks installation state for a normal business request", async () => {
-    process.env.MANAGER_MODE = "false";
-    isInstalledForRequest.mockResolvedValue(false);
-
-    const response = await handleProxyRequest(request("/"));
-
-    expect(response.status).toBe(307);
-    expect(response.headers.get("location")).toBe("https://manager.example.com/install");
-    expect(isInstalledForRequest).toHaveBeenCalledOnce();
-  });
-
-  it("preserves protected business route redirects after installation", async () => {
-    process.env.MANAGER_MODE = "false";
-    isInstalledForRequest.mockResolvedValue(true);
-
-    const response = await handleProxyRequest(request("/owner"));
-
-    expect(response.status).toBe(307);
-    expect(response.headers.get("location")).toContain("/sign-in?callbackUrl=%2Fowner");
-  });
-});
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index c3a3219..54b2541 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -1,6 +1,7 @@
 import type { Metadata, Viewport } from "next";
 import { Inter } from "next/font/google";
 import { Providers } from "@/components/providers";
+import { getBranding } from "@/lib/business/branding";
 import "./globals.css";
 
 const inter = Inter({
@@ -17,13 +18,6 @@ const inter = Inter({
  * than "NextChair" (see that file's own fallback-order comment).
  */
 export async function generateMetadata(): Promise<Metadata> {
-  if (process.env.MANAGER_MODE === "true") {
-    return {
-      title: { default: "NextChair Manager", template: "%s | NextChair Manager" },
-      description: "Manage NextChair business deployments.",
-    };
-  }
-  const { getBranding } = await import("@/lib/business/branding");
   const branding = await getBranding();
 
   return {
@@ -47,17 +41,6 @@ export async function generateMetadata(): Promise<Metadata> {
 }
 
 export async function generateViewport(): Promise<Viewport> {
-  if (process.env.MANAGER_MODE === "true") {
-    return {
-      width: "device-width",
-      initialScale: 1,
-      maximumScale: 1,
-      userScalable: false,
-      viewportFit: "cover",
-      themeColor: "#111b15",
-    };
-  }
-  const { getBranding } = await import("@/lib/business/branding");
   const branding = await getBranding();
   return {
     width: "device-width",
diff --git a/src/proxy.ts b/src/proxy.ts
index 3e2f0d8..b47e45b 100644
--- a/src/proxy.ts
+++ b/src/proxy.ts
@@ -1,6 +1,7 @@
 import NextAuth from "next-auth";
-import { NextResponse, type NextRequest } from "next/server";
+import { NextResponse } 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 +
@@ -20,6 +21,7 @@ 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",
@@ -82,23 +84,17 @@ function buildCsp(): string {
   ].join("; ");
 }
 
-export async function handleProxyRequest(req: NextRequest) {
+export default auth(async (req) => {
   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}/`),
   );
-  const { isInstalledForRequest } = await import("@/lib/installation/installation-state");
-  const installed = await isInstalledForRequest();
+  // 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();
 
   if (!installed && !isInstallExempt) {
     const response = NextResponse.redirect(new URL("/install", req.nextUrl.origin));
@@ -130,9 +126,7 @@ export async function handleProxyRequest(req: NextRequest) {
   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).*)"],