refactor(v1.4.15): apply simplify-review safe suggestions

Drop dead exports + misleading comments + unreachable defaults flagged
by phase-D simplify review (autonomous-yes items only):

- channel-state: drop unused TEST_CONSTANTS re-export
- retry-policy: drop unused RejectKind type alias
- achievements: drop misleading "fallback" comment on exhaustive switch
- notification-status-card: drop unreachable default in stateBadgeFor
- withings: export isWithingsRefreshReauthFailure + dedupe inline
  classifier in /api/withings/status route
- codex-slug-cache: drop test-only inspectCodexSlugCache helper; tests
  read getCachedCodexSlug() instead

Findings 1, 2, 8, 9 deferred to v1.4.16 (require product call).
Finding 11 is an explicit anti-finding.

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

src/app/api/withings/status/route.ts

@@ -5,6 +5,7 @@ import { apiSuccess } from "@/lib/api-response";
 import { decrypt, encrypt } from "@/lib/crypto";
 import { getUserWithingsCredentials } from "@/lib/withings/credentials";
 import { refreshAccessToken } from "@/lib/withings/client";
+import { isWithingsRefreshReauthFailure } from "@/lib/withings/sync";
 import { markReauthRequired } from "@/lib/integrations/status";
 
 /**
@@ -80,17 +81,7 @@ export const GET = apiHandler(async () => {
       // the user reconnects. We mirror the same status-code parsing
       // the sync path does.
       const message = error instanceof Error ? error.message : String(error);
-      const statusMatch = /Withings\s+\w+\s+error:\s*(\d+)/.exec(message);
-      const statusCode = statusMatch
-        ? Number.parseInt(statusMatch[1], 10)
-        : NaN;
-      const isReauth =
-        Number.isFinite(statusCode) &&
-        (statusCode === 100 ||
-          statusCode === 101 ||
-          statusCode === 102 ||
-          (statusCode >= 200 && statusCode <= 299));
-      if (isReauth) {
+      if (isWithingsRefreshReauthFailure(message)) {
         await markReauthRequired(user.id, "withings", message).catch(() => {});
       }
     }

src/components/settings/notification-status-card.tsx

@@ -327,7 +327,6 @@ function stateBadgeFor(
         icon: <Clock className="h-3 w-3" aria-hidden />,
       };
     case "manually_disabled":
-    default:
       return {
         label: t("settings.notificationStatus.stateManuallyDisabled"),
         variant: "secondary",

src/lib/ai/__tests__/codex-slug-cache.test.ts

@@ -4,7 +4,6 @@ import {
   setCachedCodexSlug,
   invalidateCachedCodexSlug,
   clearCodexSlugCache,
-  inspectCodexSlugCache,
   CODEX_SLUG_CACHE_TTL_MS,
 } from "../codex-slug-cache";
 
@@ -19,7 +18,6 @@ describe("Codex slug cache", () => {
 
   it("starts empty", () => {
     expect(getCachedCodexSlug()).toBeNull();
-    expect(inspectCodexSlugCache()).toBeNull();
   });
 
   it("set + get returns the cached slug within TTL", () => {
@@ -43,8 +41,8 @@ describe("Codex slug cache", () => {
   it("expired entry is evicted on read", () => {
     setCachedCodexSlug("gpt-5.3-codex", 1_000);
     getCachedCodexSlug(1_000 + CODEX_SLUG_CACHE_TTL_MS + 1);
-    // Subsequent inspect should be null too.
-    expect(inspectCodexSlugCache(1_000 + CODEX_SLUG_CACHE_TTL_MS + 1)).toBeNull();
+    // Subsequent get should be null too (no resurrection).
+    expect(getCachedCodexSlug(1_000 + CODEX_SLUG_CACHE_TTL_MS + 1)).toBeNull();
   });
 
   it("invalidate clears the slot", () => {
@@ -58,10 +56,4 @@ describe("Codex slug cache", () => {
     setCachedCodexSlug("b", 2_000);
     expect(getCachedCodexSlug(2_500)).toBe("b");
   });
-
-  it("inspect reports age in ms", () => {
-    setCachedCodexSlug("gpt-5.3-codex", 1_000);
-    const inspected = inspectCodexSlugCache(1_500);
-    expect(inspected).toEqual({ slug: "gpt-5.3-codex", ageMs: 500 });
-  });
 });

src/lib/ai/__tests__/codex-slug-fallback.test.ts

@@ -2,7 +2,7 @@ import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
 import { CodexClient, __test } from "../codex-client";
 import {
   clearCodexSlugCache,
-  inspectCodexSlugCache,
+  getCachedCodexSlug,
   setCachedCodexSlug,
   CODEX_SLUG_CACHE_TTL_MS,
 } from "../codex-slug-cache";
@@ -105,7 +105,7 @@ describe("Codex slug fallback chain", () => {
     expect(diagnostics?.cacheState).toBe("miss");
     expect(diagnostics?.workingSlug).toBe("gpt-5.3-codex");
 
-    expect(inspectCodexSlugCache()?.slug).toBe("gpt-5.3-codex");
+    expect(getCachedCodexSlug()).toBe("gpt-5.3-codex");
   });
 
   it("walks past first slug on 'not supported when using Codex with a ChatGPT account' 400", async () => {
@@ -134,7 +134,7 @@ describe("Codex slug fallback chain", () => {
     expect(diagnostics?.workingSlug).toBe("gpt-5.3-codex");
 
     // The working slug — not the rejected one — is now cached.
-    expect(inspectCodexSlugCache()?.slug).toBe("gpt-5.3-codex");
+    expect(getCachedCodexSlug()).toBe("gpt-5.3-codex");
   });
 
   it("walks past first slug on 400 with model_not_found body", async () => {
@@ -302,7 +302,7 @@ describe("Codex slug fallback chain", () => {
 
   it("cache invalidated when cached slug starts rejecting", async () => {
     setCachedCodexSlug("gpt-5-codex");
-    expect(inspectCodexSlugCache()?.slug).toBe("gpt-5-codex");
+    expect(getCachedCodexSlug()).toBe("gpt-5-codex");
 
     const mockFetch = vi
       .fn()
@@ -320,7 +320,7 @@ describe("Codex slug fallback chain", () => {
 
     // After walking to "gpt-5.3-codex" (the next entry after the
     // cached one), the cache is updated to the new working slug.
-    expect(inspectCodexSlugCache()?.slug).toBe("gpt-5.3-codex");
+    expect(getCachedCodexSlug()).toBe("gpt-5.3-codex");
   });
 
   it("isSlugRejection helper recognises canonical rejection bodies", () => {

src/lib/ai/codex-slug-cache.ts

@@ -59,16 +59,4 @@ export function clearCodexSlugCache(): void {
   cache.clear();
 }
 
-/**
- * Diagnostic helper — exposes (slug, ageMs) for Wide-Event annotation.
- * Returns null when nothing is cached.
- */
-export function inspectCodexSlugCache(
-  now: number = Date.now(),
-): { slug: string; ageMs: number } | null {
-  const entry = cache.get(CACHE_KEY);
-  if (!entry) return null;
-  return { slug: entry.slug, ageMs: now - entry.cachedAtMs };
-}
-
 export const CODEX_SLUG_CACHE_TTL_MS = CACHE_TTL_MS;

src/lib/gamification/achievements.ts

@@ -41,11 +41,6 @@ export interface AchievementDefinition {
   format: "count" | "days" | "percent";
 }
 
-/**
- * Stable metric → category mapping. Add a metric here when it joins the
- * `AchievementMetricKey` union; the page falls back to "engagement" if
- * a future definition slips through, so there is no silent drop-off.
- */
 export function getAchievementCategory(
   metric: AchievementMetricKey,
 ): AchievementCategory {

src/lib/notifications/channel-state.ts

@@ -8,7 +8,6 @@
 import { prisma } from "@/lib/db";
 import { auditLog } from "@/lib/auth/audit";
 import {
-  MAX_CONSECUTIVE_FAILURES,
   nextRetryAt,
   shouldAutoDisableAfterTransient,
   type SendOutcome,
@@ -167,5 +166,3 @@ export function isChannelInCooldown(
 ): boolean {
   return channel.nextRetryAt !== null && channel.nextRetryAt > now;
 }
-
-export const TEST_CONSTANTS = { MAX_CONSECUTIVE_FAILURES } as const;

src/lib/notifications/retry-policy.ts

@@ -25,8 +25,6 @@
  *    response that doesn't match the hard-reject rules.
  */
 
-export type RejectKind = "hard" | "soft" | "ok";
-
 export interface SendOutcome {
   ok: boolean;
   /** True iff the upstream signaled a permanent failure (410, blocked-by-user, …). */

src/lib/withings/sync.ts

@@ -237,7 +237,7 @@ export async function syncUserMeasurements(
  * The error message format from `refreshAccessToken()` is
  * "Withings refresh error: <status> - <error>".
  */
-function isWithingsRefreshReauthFailure(message: string): boolean {
+export function isWithingsRefreshReauthFailure(message: string): boolean {
   const status = extractWithingsStatus(message);
   if (!status) return false;
   const n = Number.parseInt(status, 10);
@@ -247,7 +247,7 @@ function isWithingsRefreshReauthFailure(message: string): boolean {
   return false;
 }
 
-function extractWithingsStatus(message: string): string | undefined {
+export function extractWithingsStatus(message: string): string | undefined {
   // Captures the digit run after "Withings <verb> error:" — same shape
   // exchangeCode and refreshAccessToken use.
   const m = /Withings\s+\w+\s+error:\s*(\d+)/.exec(message);