Keep prod health checks and route fallbacks from failing on stale API entries

Add a Bun health script that exercises top-level, dynamic, and representative video routes against one or more hosts so prod regressions are visible from a single command.

Device pages now fall back to the bundled device list when the external API misses a slug, and orphaned tv slugs redirect to /benchmarks instead of returning a 500. Video fallback logic reuses the existing YouTube-to-listing builder so route reconstruction stays aligned with the current build logic.

Constraint: The external API host can lag behind the frontend build and omit per-slug JSON files that public routes still expect
Rejected: Import the generated video list directly | static/video-list.json is too large for a safe SSR fallback
Rejected: Leave missing tv routes as 500s | a stale public URL should degrade to a useful redirect instead of breaking the request
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep route fallbacks tied to build-time artifacts from the same repo so frontend and fallback data stay in sync
Tested: bun scripts/health http://127.0.0.1:4322; vitest ./test/prebuild/config-node.test.js ./test/prebuild/site-listings.test.js; pnpm run netlify-build
Not-tested: live production deploy before push

test/prebuild/site-listings.test.js

@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+    getDeviceListingBySlug,
+    getVideoListingBySlug
+} from '~/helpers/site-listings.js'
+
+describe( 'site listing fallbacks', () => {
+    it( 'loads known devices from the bundled device list', () => {
+        expect( getDeviceListingBySlug( 'm1-imac' ) ).toMatchObject({
+            name: 'M1 iMac',
+            endpoint: '/device/m1-imac'
+        })
+    })
+
+    it( 'rebuilds known tv listings from the bundled YouTube source', async () => {
+        await expect(
+            getVideoListingBySlug( 'install-instagram-app-on-m1-macbook-air-apple-silicon-tutorial-i-vfbmworal6i' )
+        ).resolves.toMatchObject({
+            endpoint: '/tv/install-instagram-app-on-m1-macbook-air-apple-silicon-tutorial-i-vfbmworal6i'
+        })
+    })
+
+    it( 'returns null for missing tv slugs', async () => {
+        await expect(
+            getVideoListingBySlug( 'apple-silicon-gaming-is-here' )
+        ).resolves.toBeNull()
+    })
+})