feat(cloudflare): configure CDN warmup promotion delay

[james-elicx]

Summary

• add --warm-cdn-promotion-delay <ms>
• retain 15,000 ms as the default pre-promotion propagation delay
• accept zero to promote immediately after successful warmup
• skip the delay entirely when promotion is disabled

Test plan

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

Stacked on #3016.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@vinext/cloudflare@3017

npm i https://pkg.pr.new/create-vinext-app@3017

npm i https://pkg.pr.new/@vinext/types@3017

npm i https://pkg.pr.new/vinext@3017

commit: 134a34b

[github-actions]

Performance benchmarks

Compared 134a34b against base 17fe916 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	129.1 KB	129.2 KB	⚫ +0.0%
Dev server cold start	vinext	3.15 s	3.08 s	🟢 -2.2%
Production build time	vinext	3.37 s	3.34 s	⚫ -0.9%
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