fix(cloudflare): default CDN warmup concurrency to 25

[james-elicx]

Summary

• raise the default CDN warmup concurrency from 10 to 25
• document the default in deploy help
• preserve --warm-cdn-concurrency as an explicit override

Test plan

• vp test run tests/cloudflare-cdn-warm.test.ts tests/cloudflare-cdn-warm-deploy.test.ts tests/deploy.test.ts
• vp check packages/cloudflare/src/cdn-warm.ts packages/cloudflare/src/deploy-help.ts tests/cloudflare-cdn-warm.test.ts

Stacked on #3002.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vinext/cloudflare@3015

npm i https://pkg.pr.new/create-vinext-app@3015

npm i https://pkg.pr.new/@vinext/types@3015

npm i https://pkg.pr.new/vinext@3015

commit: 2a86cec

[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

[github-actions]

Performance benchmarks

Compared 2a86cec against base d5663fb using alternating same-runner rounds. Next.js was unchanged and skipped.

1 improved · 0 regressed · 5 within ±1.5%

Scenario	Framework	Baseline	Current	Change
Client bundle size (gzip)	vinext	141.8 KB	141.8 KB	⚫ -0.0%
Client entry size (gzip)	vinext	129.2 KB	129.1 KB	⚫ -0.0%
Dev server cold start	vinext	3.33 s	3.24 s	🟢 -2.5%
Production build time	vinext	3.56 s	3.55 s	⚫ -0.4%
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}