fix(cloudflare): complete warmup response and promotion contracts

[james-elicx]

Summary

Consolidates the deployed HTML proof and terminal/no-promote response handling previously split across #3041–#3046.

• prove the first post-promotion Pages and App HTML requests are untouched CDN hits from the uploaded build
• reject no-promote mode when discovery is empty, HTML identity is unverifiable, readiness fails, or any warm request remains unsuccessful
• validate complete Pages getStaticPaths() results rather than emitting partial plans
• skip same-build 3xx/404 responses only when cache policy and Cloudflare admission explicitly prove they are non-cacheable
• warm admitted cacheable redirects and not-found responses after the same content, build, and Vary validation as successful responses
• continue rejecting 5xx, wrong-build, unsupported variants, and contradictory cache policy

Scope

Only CDN warm response classification, no-promote completion semantics, and deployed proof for discovered ISR keys. Application status codes, rendering, middleware, and general cache policy are unchanged.

Validation

The retained commits keep their focused warm/deploy/discovery tests and deployed App/Pages HTML assertions. The cumulative exact head has passed the complete CI suite and deployed browser-reuse proof.

Consolidates #3041 through #3046. Stacked on #3040.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vinext/cloudflare@3046

npm i https://pkg.pr.new/create-vinext-app@3046

npm i https://pkg.pr.new/@vinext/types@3046

npm i https://pkg.pr.new/vinext@3046

commit: fa424bc

[github-actions]

Performance benchmarks

Compared fa424bc against base d7794d6 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	3.11 s	3.08 s	⚫ -0.7%
Production build time	vinext	3.46 s	3.50 s	⚫ +1.2%
RSC entry closure size (gzip)	vinext	116.0 KB	116.0 KB	⚫ +0.0%
Server bundle size (gzip)	vinext	197.5 KB	197.5 KB	⚫ +0.0%

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
web	preview	production