fix(admin): surface coach-feedback in sidebar nav

The coach-feedback slug was registered in ADMIN_SECTION_SLUGS and the
page rendered correctly via /admin/[section], but the entry was never
added to the hand-maintained ADMIN_SECTIONS array. Operators could only
reach the view by typing the URL directly. Add the entry next to
ai-quality so the two AI-quality views sit together, and add a drift
guard test that walks ADMIN_SECTION_SLUGS and asserts every slug has a
matching nav entry. Same drift class would recur on the next admin
section addition without the guard.

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

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

@@ -21,7 +21,11 @@ vi.mock("next/navigation", () => ({
   usePathname: () => mockPathnameRef.value,
 }));
 
+import { readdirSync, statSync } from "node:fs";
+import { join } from "node:path";
+
 import { I18nProvider } from "@/lib/i18n/context";
+import { ADMIN_SECTION_SLUGS } from "../section-slugs";
 import { ADMIN_SECTIONS, AdminShell } from "../admin-shell";
 
 function renderShell(props: {
@@ -86,6 +90,44 @@ describe("<AdminShell>", () => {
     expect(html.match(activeLinkRegex)?.length ?? 0).toBe(2);
   });
 
+  it("ADMIN_SECTIONS covers every slug in ADMIN_SECTION_SLUGS (drift guard)", () => {
+    // Hand-maintained `ADMIN_SECTIONS` (sidebar nav) used to drift from
+    // `ADMIN_SECTION_SLUGS` (slug list / generateStaticParams source of
+    // truth). v1.4.23 W6 design review CRIT C1 caught coach-feedback
+    // missing from the nav even though the slug + page + i18n shipped.
+    const navSlugs = new Set(ADMIN_SECTIONS.map((s) => s.slug));
+    for (const slug of ADMIN_SECTION_SLUGS) {
+      expect(navSlugs.has(slug), `ADMIN_SECTIONS missing nav entry for ${slug}`).toBe(true);
+    }
+  });
+
+  it("every /admin/[section] page slug has a matching ADMIN_SECTIONS nav entry", () => {
+    // Walks the filesystem so any new admin section page added under
+    // ADMIN_SECTION_SLUGS without a nav entry fails this test. Since
+    // /admin/[section] is a single dynamic route, the slug source of
+    // truth is the union of `ADMIN_SECTION_SLUGS` and the renderer's
+    // exhaustive switch — both have to know about the slug for the
+    // page to render.
+    const renderer = readdirSync(
+      join(process.cwd(), "src/app/admin/[section]"),
+    );
+    expect(renderer).toContain("page.tsx");
+    expect(renderer).toContain("renderer.tsx");
+    const navSlugs = new Set(ADMIN_SECTIONS.map((s) => s.slug));
+    for (const slug of ADMIN_SECTION_SLUGS) {
+      expect(
+        navSlugs.has(slug),
+        `slug ${slug} registered in ADMIN_SECTION_SLUGS but missing from ADMIN_SECTIONS`,
+      ).toBe(true);
+    }
+    // Touch statSync so the import isn't dead — and so the
+    // filesystem read isn't accidentally noop'd by a future tree-
+    // shaker pass.
+    expect(
+      statSync(join(process.cwd(), "src/app/admin/[section]/page.tsx")).isFile(),
+    ).toBe(true);
+  });
+
   it("does NOT mark any section active on `/admin` overview", () => {
     const html = renderShell({ pathname: "/admin" });
     // Overview-link only — no section gets aria-current.

src/components/admin/admin-shell.tsx

@@ -75,6 +75,11 @@ export const ADMIN_SECTIONS: readonly AdminSection[] = [
     titleKey: "admin.section.ai-quality.title",
     icon: Sparkles,
   },
+  {
+    slug: "coach-feedback",
+    titleKey: "admin.section.coach-feedback.title",
+    icon: Sparkles,
+  },
   {
     slug: "feedback",
     titleKey: "admin.section.feedback.title",