fix(cloudflare): prewarm routed response stages

[james-elicx]

Part 13 of 16 in the staged CDN adapter stack. Depends on #3152.

Summary

• prewarms cacheable URLs through the routed response-stage path
• keeps explicit warm targets, discovered App/Pages routes, draft exclusion, and probe artifacts aligned
• preserves main's per-route Worker-version propagation wait before classifying a staged route
• verifies deployed App HTML, Pages HTML/data, and RSC reuse while middleware/config headers remain request-specific
• verifies deployed CF-Cache-Status MISS/HIT values are mirrored through both vinext/Next.js cache headers

Validation

• 507 focused Cloudflare probe, warm, and deploy tests passed
• local Cloudflare E2E: 16 passed, 1 deploy-only skip
• PPR cacheability E2E: 8 passed

Review size

• Implementation: +279 / -86 LOC
• Tests and fixtures: +703 / -6 LOC
• Other (docs, config, lockfile): +57 / -5 LOC
• 13 changed files

Measured against codex/cdn-v2-cloudflare-entrypoints after rebasing onto main@a6931c0.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vinext/cloudflare@3153

npm i https://pkg.pr.new/create-vinext-app@3153

npm i https://pkg.pr.new/@vinext/types@3153

npm i https://pkg.pr.new/vinext@3153

commit: 4518eee

[github-actions]

Performance benchmarks

Compared 4518eee against base e91dec5 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	142.3 KB	142.3 KB	⚫ +0.0%
Client entry size (gzip)	vinext	129.6 KB	129.6 KB	⚫ +0.0%
Dev server cold start	vinext	2.51 s	2.50 s	⚫ -0.2%
Production build time	vinext	2.69 s	2.70 s	⚫ +0.4%
RSC entry closure size (gzip)	vinext	125.6 KB	125.6 KB	⚫ +0.0%
Server bundle size (gzip)	vinext	216.4 KB	216.4 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
static-export	preview	production
web	preview	production