Improve local auth env handling and fallbacks

Allow local env files to reliably override authentication feature flags (SMS/WeChat) by whitelisting keys in scripts/dev-utils.mjs and adding a unit test. Add SMS checks to scripts/check-api-server-env.mjs. Make server config.parse_bool tolerant of shell-wrapped quoted values (e.g. '"true"') and add tests so SMS_AUTH_ENABLED is parsed correctly when shells supply quotes. Update docs to clarify SMS env behaviour, restart requirements, and add guidance + a CSS fallback for old mobile browsers (QQ/X5) so public cover images render even when aspect-ratio is unsupported. Also include related frontend test and component adjustments and add puzzle onboarding handlers/endpoints in server-rs/crates/api-server/src/puzzle.rs.

src/components/rpg-entry/RpgEntryHomeView.recharge.test.tsx

@@ -387,16 +387,24 @@ vi.mock('../../services/rpg-entry/rpgProfileClient', () => ({
 vi.mock('../ResolvedAssetImage', () => ({
   ResolvedAssetImage: ({
     src,
+    fallbackSrc,
     alt,
     className,
     ...rest
   }: {
     src?: string | null;
+    fallbackSrc?: string | null;
     alt?: string;
     className?: string;
   }) =>
     src ? (
-      <img src={src} alt={alt ?? ''} className={className} {...rest} />
+      <img
+        src={src}
+        data-fallback-src={fallbackSrc ?? undefined}
+        alt={alt ?? ''}
+        className={className}
+        {...rest}
+      />
     ) : null,
 }));
 
@@ -2901,6 +2909,36 @@ test('mobile discover recommend feed only rotates the card closest to screen cen
   );
 });
 
+test('mobile discover recommend feed renders cover fallback for legacy browsers', async () => {
+  renderStatefulLoggedOutHomeView({
+    latestEntries: [
+      {
+        ...puzzlePublicEntry,
+        coverImageSrc:
+          '/generated-puzzle-assets/puzzle-session-1/cover/image.png',
+      },
+    ],
+  });
+
+  const discoverPanel = document.getElementById('platform-tab-panel-category');
+  if (!discoverPanel) {
+    throw new Error('缺少发现面板');
+  }
+
+  const card = within(discoverPanel).getByRole('button', { name: /奇幻拼图/u });
+  const cover = card.querySelector('.platform-public-work-card__cover');
+  const image = within(card).getByRole('img');
+
+  expect(cover).toBeTruthy();
+  expect(cover?.className).toContain('platform-public-work-card__cover');
+  expect(image.getAttribute('src')).toBe(
+    '/generated-puzzle-assets/puzzle-session-1/cover/image.png',
+  );
+  expect(image.getAttribute('data-fallback-src')).toBe(
+    '/creation-type-references/puzzle.webp',
+  );
+});
+
 test('mobile today channel only shows newly published works from today', async () => {
   const user = userEvent.setup();
   const now = new Date();