fix(coach): dock the conversations panel flush against the right edge

The Coach page cancelled the shell's container padding with negative
margins, so <main> kept its reserved scrollbar gutter and painted a dead
strip to the right of the panel on classic-scrollbar platforms. The shell
now renders /coach full bleed: no centred container, no padding and no
reserved gutter, and the page fills what <main> leaves below the top bar.
A refusal card (shared record, module off) keeps the padded frame.

The panel header takes one 12 px inset with a gap of 8 between title and
icons, a text-lg title, and 28 px icon buttons beside a pointer (44 px on
touch). Conversation rows take the control radius and a 36 px pointer
floor.

src/components/insights/coach-panel/conversations-panel.tsx

@@ -146,14 +146,14 @@ export function ConversationsPanel({
   const header = (inSheet: boolean) => (
     <div
       data-slot="coach-conversations-panel-header"
-      className="border-border flex h-14 shrink-0 items-center gap-1 border-b pr-2 pl-3"
+      className="border-border flex shrink-0 items-center gap-2 border-b p-3"
     >
       {inSheet ? (
-        <SheetTitle className="min-w-0 flex-1 truncate text-sm font-semibold">
+        <SheetTitle className="min-w-0 flex-1 truncate text-lg leading-tight font-semibold">
           {t("insights.coach.historyTitle")}
         </SheetTitle>
       ) : (
-        <h2 className="min-w-0 flex-1 truncate text-sm font-semibold">
+        <h2 className="min-w-0 flex-1 truncate text-lg leading-tight font-semibold">
           {t("insights.coach.historyTitle")}
         </h2>
       )}
@@ -161,7 +161,7 @@ export function ConversationsPanel({
         asChild
         variant="ghost"
         size="icon"
-        className="text-muted-foreground hover:text-foreground size-11 shrink-0 sm:size-9"
+        className="text-muted-foreground hover:text-foreground size-11 shrink-0 md:size-7"
       >
         <Link
           href="/coach/plans"
@@ -169,7 +169,7 @@ export function ConversationsPanel({
           aria-label={t("coach.plans.title")}
           title={t("coach.plans.title")}
         >
-          <Target className="size-4" aria-hidden="true" />
+          <Target className="size-5 md:size-4" aria-hidden="true" />
         </Link>
       </Button>
       <CoachSettingsOverlay
@@ -179,6 +179,7 @@ export function ConversationsPanel({
           if (!next) setSettingsOnData(false);
         }}
         focusData={settingsOnData}
+        className="md:size-7 [&_svg]:size-5 md:[&_svg]:size-4"
       />
       {inSheet ? (
         <SheetClose asChild>
@@ -189,9 +190,9 @@ export function ConversationsPanel({
             data-slot="coach-panel-close"
             aria-label={t("common.close")}
             title={t("common.close")}
-            className="text-muted-foreground hover:text-foreground size-11 shrink-0 sm:size-9"
+            className="text-muted-foreground hover:text-foreground size-11 shrink-0 md:size-7"
           >
-            <X className="size-4" aria-hidden="true" />
+            <X className="size-5 md:size-4" aria-hidden="true" />
           </Button>
         </SheetClose>
       ) : null}

src/components/insights/coach-panel/history-rail.tsx

@@ -294,7 +294,7 @@ function HistoryRow({
         title={c.title}
         data-slot="coach-history-select"
         className={cn(
-          "flex min-h-11 w-full min-w-0 items-center gap-1.5 rounded-lg py-2 pr-11 pl-2 text-left text-sm transition-colors",
+          "flex min-h-11 w-full min-w-0 items-center gap-1.5 rounded-md py-2 pr-11 pl-2 text-left text-sm transition-colors sm:min-h-9",
           "focus-visible:ring-ring/50 focus-visible:ring-2 focus-visible:outline-none",
           // The open conversation reads like the open page in the left
           // navigation: the same primary wash, so the two rails agree.

src/components/layout/auth-shell.tsx

@@ -27,12 +27,19 @@ import { DemoBanner } from "./demo-banner";
 import { OfflineBanner } from "./offline-banner";
 import { SharedRecordBanner } from "./shared-record-banner";
 import { SharedRecordUnavailable } from "./shared-record-unavailable";
-import { ModulePageGate } from "@/components/layout/module-page-gate";
+import {
+  isModulePageOff,
+  ModulePageGate,
+} from "@/components/layout/module-page-gate";
+import { cn } from "@/lib/utils";
 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`
@@ -141,6 +148,17 @@ 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 &&
+    !isModulePageOff(pathname, user?.modules);
   // 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.
@@ -461,7 +479,10 @@ export function AuthShell({
               // window. Anchoring the scroll container closes the escape route
               // for all of them at once instead of asking each new
               // absolutely-positioned child to remember its own wrapper.
-              className="relative flex-1 [scrollbar-gutter:stable] overflow-y-auto pb-[calc(4rem+env(safe-area-inset-bottom,0px))] md:pb-0"
+              className={cn(
+                "relative flex-1 overflow-y-auto pb-[calc(4rem+env(safe-area-inset-bottom,0px))] md:pb-0",
+                fullBleed ? "flex flex-col" : "[scrollbar-gutter:stable]",
+              )}
             >
               {/*
               v1.4.33 IW9 — container normalised on `max-w-screen-xl`
@@ -479,7 +500,12 @@ export function AuthShell({
             */}
               <div
                 data-slot="main-content-wrapper"
-                className="mx-auto max-w-screen-xl px-4 pt-6 pb-20 md:px-6"
+                data-full-bleed={fullBleed ? "true" : undefined}
+                className={
+                  fullBleed
+                    ? "flex min-h-0 flex-1 flex-col"
+                    : "mx-auto max-w-screen-xl px-4 pt-6 pb-20 md:px-6"
+                }
               >
                 {outsideSharedRecord ? (
                   <SharedRecordUnavailable />

src/components/layout/module-page-gate.tsx

@@ -74,14 +74,24 @@ export function moduleOwningPath(pathname: string): ModuleKey | undefined {
  * only after the account payload resolved, so the map is never read on a
  * hydration render.
  */
+/** True when the module that owns `pathname` is switched off. */
+export function isModulePageOff(
+  pathname: string,
+  modules: Partial<Record<ModuleKey, boolean>> | null | undefined,
+): boolean {
+  const moduleKey = moduleOwningPath(pathname);
+  return moduleKey !== undefined && modules?.[moduleKey] === false;
+}
+
 export function ModulePageGate({ children }: { children: ReactNode }) {
   const pathname = usePathname();
   const { user } = useAuth();
   const { t } = useTranslations();
 
   const moduleKey = moduleOwningPath(pathname);
-  const off = moduleKey !== undefined && user?.modules?.[moduleKey] === false;
-  if (!off) return <>{children}</>;
+  if (moduleKey === undefined || !isModulePageOff(pathname, user?.modules)) {
+    return <>{children}</>;
+  }
 
   const destination = NAV_DESTINATIONS.find((d) =>
     isNavDestinationActive(d.href, pathname),