fix(cloudflare): discover prewarm paths from staged worker

[james-elicx]

Capability stack 2/9. Exact head: b3b23e7092858d70ae7b8ae3646e063da3c49029. Base: #3108.

Full chain: #3108 → #3090 → #3091 → #3092 → #3103 → #3093 → #3094 → #3098 → #3113.

Summary

• upload and stage the exact Worker version at 0% before prerender path discovery
• run authenticated App and Pages discovery against that staged Worker so generateStaticParams and getStaticPaths can use real Cloudflare bindings
• feed the discovered concrete HTML, RSC, and loading-shell identities into CDN warming
• share one build-scoped capability across hybrid App/Pages bundles and strip it before user code
• retry transient platform routing failures within a bounded discovery phase while keeping structured user-function failures fatal
• keep the deadline regression stable under loaded CI by allowing the intended third hung request to start before the shared deadline
• keep ordinary request paths free of discovery URL parsing and lazily load Pages discovery code

This layer moves route discovery into the staged Worker. It does not classify App Pages, emit a cacheability manifest, alter ordinary CDN admission, perform the second upload, or certify cache fills.

Review guide

1. packages/cloudflare/src/deploy.ts owns upload → 0% stage → triggers → discovery → readiness → warm → promotion.
2. packages/vinext/src/build/prerender-paths.ts performs bounded remote discovery.
3. packages/vinext/src/server/worker-prerender-discovery.ts authenticates internal discovery.
4. App and Pages production entries expose the endpoints only to the authenticated discovery context.
5. The workers-cache example reads KV during generateStaticParams, proving binding-backed discovery.

Review size

Layer-only diff against this PR's base: 27 files, +1,183/-152.

Validation

• vp test run tests/prerender-paths.test.ts — 53/53 on the prior cumulative Pages head
• staged-discovery deadline regression repeated 5/5 without wall-clock flake
• layer exact-head CI and deployed workers-cache coverage are green
• current full-stack cumulative changed-file suites — 2,864/2,864
• current full-stack PPR probe/admission/Pages built-workerd E2E — 8/8
• current full-stack vp check and git diff --check

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vinext/cloudflare@3090

npm i https://pkg.pr.new/create-vinext-app@3090

npm i https://pkg.pr.new/@vinext/types@3090

npm i https://pkg.pr.new/vinext@3090

commit: b3b23e7

[github-actions]

Performance benchmarks

Compared b3b23e7 against base 1fd53d7 using alternating same-runner rounds. Next.js was unchanged and skipped.

0 improved · 0 regressed · 6 within ±1.5%

Scenario	Framework	Baseline	Current	Change
Client bundle size (gzip)	vinext	142.2 KB	142.2 KB	⚫ +0.0%
Client entry size (gzip)	vinext	129.5 KB	129.5 KB	⚫ +0.0%
Dev server cold start	vinext	2.38 s	2.36 s	⚫ -0.8%
Production build time	vinext	2.58 s	2.57 s	⚫ -0.3%
RSC entry closure size (gzip)	vinext	116.6 KB	116.7 KB	⚫ +0.1%
Server bundle size (gzip)	vinext	198.1 KB	198.3 KB	⚫ +0.1%

View detailed results and traces

_{🟢 improvement · 🔴 regression · ⚫ change below 1.5% · paired base/head}

[github-actions]

Example	Preview	Production	Original
app-router-cloudflare	preview	production
pages-router-cloudflare	preview	production
app-router-playground	preview	production	original
realworld-api-rest	preview	production
nextra-docs-template	preview	production
benchmarks	preview	production
hackernews	preview	production	original
workers-cache	preview	production
static-export	preview	production
web	preview	production