fix(admin): suppress painted scrollbar on mobile section strip

Production probe at /admin/api-tokens on a Pixel-5 viewport pinned the
scrollbar that kept showing up after two earlier fixes: it lives in
the AdminShell mobile section strip (13 entries, scrollWidth ~1700 vs
clientWidth ~360), not in the api-tokens table. The strip sits right
above the api-tokens card, which is why every previous attempt
targeted the table while the bar stayed put.

Adds a `no-scrollbar` utility in globals.css (scrollbar-width: none +
::-webkit-scrollbar { display: none }) and applies it to the strip in
both AdminShell and SettingsShell. Swipe and keyboard-arrow scrolling
keep working; the painted bar simply doesn't draw.

New AdminShell unit suite locks in the class so a future refactor
can't silently regress it; settings-shell test gets the matching
assertion. The api-tokens e2e spec gains a regression check that the
strip declares `no-scrollbar` and overflow-x-auto together.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

e2e/admin-api-tokens-mobile.spec.ts

@@ -74,4 +74,48 @@ test.describe("/admin/api-tokens mobile no-overflow", () => {
       `scrollWidth=${dims.scrollWidth}, innerWidth=${dims.innerWidth}`,
     ).toBeLessThanOrEqual(dims.innerWidth + 1);
   });
+
+  // v1.4.18 phase A2 — production probe at Pixel-5 viewport pinned the
+  // visible "scrollbar" Marc reported for the third time as the
+  // `<AdminShell>` mobile section strip, NOT the api-tokens table. The
+  // strip carries 13 admin sections so its scrollWidth (~1700 CSS px)
+  // permanently exceeds clientWidth (~360 CSS px). Adding the
+  // `no-scrollbar` utility class (`globals.css`) suppresses the
+  // painted bar while preserving swipe + keyboard-arrow scrolling.
+  // This regression guard fails if a future refactor drops the class.
+  test("Pixel-5 viewport: admin section strip suppresses its painted scrollbar", async ({
+    page,
+  }) => {
+    await page.route("**/api/admin/tokens", (route) =>
+      route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({ data: [], error: null }),
+      }),
+    );
+
+    await page.goto("/admin/api-tokens", { waitUntil: "domcontentloaded" });
+    await page.waitForLoadState("networkidle");
+
+    // Find the mobile strip (`<nav aria-label>` matches both English
+    // "Admin sections" and German "Admin-Bereiche").
+    const strip = page.locator("nav.no-scrollbar.overflow-x-auto").first();
+    await expect(strip).toBeAttached();
+
+    // The strip itself must declare `no-scrollbar` so the painted
+    // horizontal scrollbar — which production showed at Pixel-5 — is
+    // suppressed.
+    const cls = await strip.getAttribute("class");
+    expect(cls ?? "").toContain("no-scrollbar");
+    expect(cls ?? "").toContain("overflow-x-auto");
+
+    // And the strip must still carry useful overflow internally
+    // (clientWidth < scrollWidth), proving scroll behaviour isn't
+    // disabled — only the bar is invisible.
+    const stripDims = await strip.evaluate((el) => ({
+      scrollWidth: (el as HTMLElement).scrollWidth,
+      clientWidth: (el as HTMLElement).clientWidth,
+    }));
+    expect(stripDims.scrollWidth).toBeGreaterThan(stripDims.clientWidth);
+  });
 });

src/app/globals.css

@@ -199,6 +199,29 @@
   }
 }
 
+/*
+ * `.no-scrollbar` — keeps a container scrollable but hides the visible
+ * bar. Used by the mobile section strips in `<AdminShell>` and
+ * `<SettingsShell>` so 13 admin / 10 settings entries can swipe
+ * horizontally without painting an always-on scrollbar at the top of
+ * every admin/settings page (a recurring Marc complaint — most
+ * recently mistaken for a `/admin/api-tokens` table scrollbar in
+ * v1.4.16/17 because the strip sits right above the api-tokens card).
+ *
+ * Standard `scrollbar-width: none` (Firefox) + `::-webkit-scrollbar`
+ * (Chromium/WebKit) covers every browser HealthLog targets. Touch
+ * scrolling, keyboard arrow scrolling, and `Tab` focus traversal all
+ * keep working — this is a purely cosmetic suppression, not an
+ * `overflow: hidden`.
+ */
+.no-scrollbar {
+  scrollbar-width: none;
+  -ms-overflow-style: none;
+}
+.no-scrollbar::-webkit-scrollbar {
+  display: none;
+}
+
 /* ── Insight card animations ─────────────────────── */
 @keyframes insight-fade-in {
   from {

src/components/admin/__tests__/admin-shell.test.tsx

@@ -0,0 +1,100 @@
+import { describe, expect, it, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+/**
+ * `<AdminShell>` mirrors `<SettingsShell>`: a sticky desktop sidebar
+ * plus a horizontal section strip on mobile. With 13 sections the strip
+ * is always wider than a 393 CSS-px (Pixel-5) viewport, so v1.4.18
+ * phase A2 added the `no-scrollbar` class to the strip — Chromium /
+ * WebKit otherwise paint an always-on horizontal scrollbar at the top
+ * of every admin page, which Marc kept mis-attributing to the
+ * `/admin/api-tokens` table card right below it. Three previous fix
+ * attempts (v1.4.15 column-hide, v1.4.16 mobile-card-list, then this
+ * one) all targeted the table while the bar lived in the shell.
+ *
+ * This suite locks in the shell-level fix so a future refactor can't
+ * silently regress it.
+ */
+
+const mockPathnameRef = { value: "/admin/system-status" };
+vi.mock("next/navigation", () => ({
+  usePathname: () => mockPathnameRef.value,
+}));
+
+import { I18nProvider } from "@/lib/i18n/context";
+import {
+  ADMIN_SECTIONS,
+  AdminShell,
+} from "../admin-shell";
+
+function renderShell(props: {
+  active?: (typeof ADMIN_SECTIONS)[number]["slug"];
+  pathname?: string;
+}) {
+  mockPathnameRef.value = props.pathname ?? "/admin/system-status";
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale="en">
+      <AdminShell active={props.active}>
+        <div>section body</div>
+      </AdminShell>
+    </I18nProvider>,
+  );
+}
+
+describe("<AdminShell>", () => {
+  it("renders every section link in both the mobile strip and the desktop sidebar", () => {
+    const html = renderShell({ active: "system-status" });
+    for (const section of ADMIN_SECTIONS) {
+      const matches = html.match(
+        new RegExp(`href="/admin/${section.slug}"`, "g"),
+      );
+      // Two renders — mobile strip + desktop sidebar.
+      expect(matches?.length ?? 0).toBe(2);
+    }
+  });
+
+  it("mobile section strip uses `no-scrollbar` so the swipe area doesn't paint a horizontal scrollbar", () => {
+    // The 13-section strip is ~1700 CSS px wide. Without
+    // `no-scrollbar` (defined in `globals.css`) Chromium/WebKit paint
+    // an always-on horizontal scrollbar at the top of every admin
+    // page. Production probe at https://healthlog.bombeck.io/admin/
+    // api-tokens at Pixel-5 viewport pins this as the *only* element
+    // with `overflow-x:auto AND scrollWidth > clientWidth`, so the
+    // class is the load-bearing fix.
+    const html = renderShell({ active: "api-tokens" });
+    const nav = html.match(/<nav\b[^>]*md:hidden[^>]*>/);
+    expect(nav).not.toBeNull();
+    expect(nav![0]).toMatch(/\bno-scrollbar\b/);
+    // Scroll behaviour itself is preserved — the strip still uses
+    // `overflow-x-auto` so swipe / keyboard-arrow scrolling continues
+    // to work, only the painted bar is suppressed.
+    expect(nav![0]).toMatch(/\boverflow-x-auto\b/);
+  });
+
+  it('marks the active section with aria-current="page" in both layouts', () => {
+    const html = renderShell({ active: "api-tokens" });
+    const occurrences = html.match(/aria-current="page"/g);
+    // Two layouts (mobile strip + desktop sidebar) → two matches.
+    expect(occurrences?.length ?? 0).toBe(2);
+    // Active link is on the api-tokens href in both renders.
+    const activeLinkRegex =
+      /<a\b[^>]*\baria-current="page"[^>]*\bhref="\/admin\/api-tokens"|<a\b[^>]*\bhref="\/admin\/api-tokens"[^>]*\baria-current="page"/g;
+    expect(html.match(activeLinkRegex)?.length ?? 0).toBe(2);
+  });
+
+  it("derives the active slug from the current pathname when `active` is omitted", () => {
+    const html = renderShell({ pathname: "/admin/api-tokens" });
+    const activeLinkRegex =
+      /<a\b[^>]*\baria-current="page"[^>]*\bhref="\/admin\/api-tokens"|<a\b[^>]*\bhref="\/admin\/api-tokens"[^>]*\baria-current="page"/g;
+    expect(html.match(activeLinkRegex)?.length ?? 0).toBe(2);
+  });
+
+  it("does NOT mark any section active on `/admin` overview", () => {
+    const html = renderShell({ pathname: "/admin" });
+    // Overview-link only — no section gets aria-current.
+    const sectionActive = html.match(
+      /aria-current="page"[^>]*\bhref="\/admin\/[^"]+"/g,
+    );
+    expect(sectionActive?.length ?? 0).toBe(0);
+  });
+});

src/components/admin/admin-shell.tsx

@@ -148,10 +148,16 @@ export function AdminShell({ active, children }: AdminShellProps) {
 
   return (
     <div className="mx-auto w-full max-w-screen-xl px-4 py-6 md:px-6 md:py-8">
-      {/* Mobile section strip — horizontal scroll, hidden on md+. */}
+      {/* Mobile section strip — horizontal scroll, hidden on md+.
+          `no-scrollbar` (defined in `globals.css`) suppresses the
+          painted scrollbar at the top of every admin page; the
+          horizontal swipe + keyboard arrow scrolling still work, the
+          bar just doesn't draw. Without this the 13-section strip
+          would render an always-on scrollbar that Marc kept
+          mis-attributing to the api-tokens table below it. */}
       <nav
         aria-label={t("admin.shell.sectionsNav")}
-        className="-mx-4 mb-4 overflow-x-auto px-4 md:hidden"
+        className="no-scrollbar -mx-4 mb-4 overflow-x-auto px-4 md:hidden"
       >
         <ul className="flex min-w-max gap-2">
           {ADMIN_SECTIONS.map((section) => {

src/components/settings/__tests__/settings-shell.test.tsx

@@ -166,4 +166,18 @@ describe("<SettingsShell>", () => {
     const html = renderShell({ active: "account", locale: "en" });
     expect(html).not.toContain("settings.sections.");
   });
+
+  it("mobile section strip uses `no-scrollbar` so the swipe area doesn't paint a horizontal scrollbar", () => {
+    // The 10-section strip is wider than 393 CSS px, so without
+    // `no-scrollbar` Chromium/WebKit paints an always-on horizontal
+    // scrollbar at the top of every settings page. The class is
+    // defined in `globals.css` and combines `scrollbar-width: none`
+    // (Firefox) with `::-webkit-scrollbar { display: none }` (everyone
+    // else) — scroll behaviour is preserved.
+    const html = renderShell({ active: "account" });
+    const nav = html.match(/<nav\b[^>]*md:hidden[^>]*>/);
+    expect(nav).not.toBeNull();
+    expect(nav![0]).toMatch(/\bno-scrollbar\b/);
+    expect(nav![0]).toMatch(/\boverflow-x-auto\b/);
+  });
 });

src/components/settings/settings-shell.tsx

@@ -131,10 +131,16 @@ export function SettingsShell({ active, children }: SettingsShellProps) {
 
   return (
     <div className="mx-auto w-full max-w-screen-xl px-4 py-6 md:px-6 md:py-8">
-      {/* Mobile section strip — horizontal scroll, hidden on md+. */}
+      {/* Mobile section strip — horizontal scroll, hidden on md+.
+          `no-scrollbar` (defined in `globals.css`) suppresses the
+          painted scrollbar; the horizontal swipe + keyboard arrow
+          scrolling still work. Without it the 10-section strip
+          renders an always-on scrollbar at the top of every settings
+          page, which makes the page feel like every section card has
+          an overflow problem. */}
       <nav
         aria-label={t("settings.shell.sectionsNav")}
-        className="-mx-4 mb-4 overflow-x-auto px-4 md:hidden"
+        className="no-scrollbar -mx-4 mb-4 overflow-x-auto px-4 md:hidden"
       >
         <ul className="flex min-w-max gap-2">
           {SETTINGS_SECTIONS.map((section) => {