test(shell): pin the full-bleed condition to exactly /coach

The condition moves out of the shell into isFullBleedPage(), a pure
helper with its own test: /coach renders edge to edge; /coach/plans,
/coach/conversations, a trailing slash, look-alike paths and other
routes keep the padded frame, and so does a refusal on /coach (outside a
shared record, module off).

src/components/layout/__tests__/full-bleed.test.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from "vitest";
+
+import { isFullBleedPage } from "../full-bleed";
+
+const open = { outsideSharedRecord: false, moduleOff: false };
+
+describe("isFullBleedPage", () => {
+  it("renders /coach edge to edge", () => {
+    expect(isFullBleedPage({ pathname: "/coach", ...open })).toBe(true);
+  });
+
+  it.each([
+    "/coach/plans",
+    "/coach/conversations",
+    "/coach/",
+    "/coaching",
+    "/",
+    "/insights",
+    "/insights/coach",
+    "/settings/ai",
+    "/documents",
+  ])("keeps %s in the padded frame", (pathname) => {
+    expect(isFullBleedPage({ pathname, ...open })).toBe(false);
+  });
+
+  it("keeps the padded frame for a refusal on /coach", () => {
+    expect(
+      isFullBleedPage({
+        pathname: "/coach",
+        outsideSharedRecord: true,
+        moduleOff: false,
+      }),
+    ).toBe(false);
+    expect(
+      isFullBleedPage({
+        pathname: "/coach",
+        outsideSharedRecord: false,
+        moduleOff: true,
+      }),
+    ).toBe(false);
+  });
+});

src/components/layout/auth-shell.tsx

@@ -32,14 +32,12 @@ import {
   switchedOffModule,
 } from "@/components/layout/module-page-gate";
 import { cn } from "@/lib/utils";
+import { isFullBleedPage } from "./full-bleed";
 import { isOnboardingPathname } from "@/lib/onboarding/wizard-steps";
 import { RecordScopeHydrationGate } from "./record-scope-hydration-gate";
 import { SidebarNav } from "./sidebar-nav";
 import { TopBar } from "./top-bar";
 
-/** The route that renders edge to edge inside the shell. */
-const COACH_FULL_BLEED_PATH = "/coach";
-
 // v1.4.27 MB6 — `/about` joins the public-path list so the GeoLite2
 // CC BY-SA 4.0 attribution stays reachable for unauthenticated
 // visitors. The `/about` route is already registered in `proxy.ts`
@@ -148,17 +146,11 @@ export function AuthShell({
     inSharedRecord &&
     !isDestinationInSharedRecord(pathname, sections) &&
     !isRecordSettingsPath;
-  // The Coach page is the one full-bleed route: its conversations panel sits
-  // flush against the right edge of the viewport and the page owns every
-  // scroll area inside it. The content box drops the centred container and
-  // `<main>` drops its reserved scrollbar gutter, which would otherwise paint
-  // a dead strip to the right of the panel on classic-scrollbar platforms.
-  // A refusal (shared record, module off) renders a card, so it keeps the
-  // ordinary padded frame.
-  const fullBleed =
-    pathname === COACH_FULL_BLEED_PATH &&
-    !outsideSharedRecord &&
-    switchedOffModule(pathname, user?.modules) === undefined;
+  const fullBleed = isFullBleedPage({
+    pathname,
+    outsideSharedRecord,
+    moduleOff: switchedOffModule(pathname, user?.modules) !== undefined,
+  });
   // The whole setup flow, not only its front door: every screen lives under
   // `/onboarding/<step>` (v1.39 C2), and an exact match here put the
   // questions inside the full app chrome, sidebar and all.

src/components/layout/full-bleed.ts

@@ -0,0 +1,27 @@
+/**
+ * Whether the shell renders a page edge to edge.
+ *
+ * The Coach page is the one full-bleed route: its conversations panel sits
+ * flush against the right edge of the viewport and the page owns every
+ * scroll area inside it. The shell then drops its centred container and
+ * padding, and `<main>` drops its reserved scrollbar gutter, which would
+ * otherwise paint a dead strip to the right of the panel on
+ * classic-scrollbar platforms.
+ *
+ * Exactly `/coach`: its sub-pages (plans, conversations) are ordinary pages
+ * in the padded frame. A refusal on `/coach` (outside a shared record, or
+ * the module switched off) renders a card, so it keeps the padded frame too.
+ */
+const FULL_BLEED_PATH = "/coach";
+
+export function isFullBleedPage(args: {
+  pathname: string;
+  outsideSharedRecord: boolean;
+  moduleOff: boolean;
+}): boolean {
+  return (
+    args.pathname === FULL_BLEED_PATH &&
+    !args.outsideSharedRecord &&
+    !args.moduleOff
+  );
+}