Add optional Cloudflare Web Analytics from a build variable

[valuecodes]

What

• Adds Cloudflare Web Analytics without committing the beacon token: the token comes from the VITE_CF_BEACON_TOKEN build variable.
• A small Vite plugin in vite.config.ts adds Cloudflare's beacon <script type="module"> to index.html only in builds where the variable is set. Unset, the page has no beacon. A malformed token fails the build.
• Documents the variable in the web README and AGENTS.md: set it as a Workers Builds build variable for production builds only, with the dashboard site on manual snippet installation.

How to test

pnpm --filter web build
VITE_CF_BEACON_TOKEN=0123456789abcdef0123456789abcdef pnpm --filter web build

The first build's dist/index.html has no cloudflareinsights script. The second has the beacon tag with data-cf-beacon.

Security review

No security-impacting changes. The existing CSP already allows the beacon's origins, and the token is validated as 32 hex digits before it goes into the HTML.

🤖 Generated with Claude Code

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-15T07:08:27.526155Z	788fc0d	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.