docs(beta): open external validation intake before 1.0 - #38

Summary

• add a public beta-testing guide with a concrete scenario matrix and current support boundary
• document a sanitized minimal TypeScript reproduction workflow and evidence checklist
• route early feedback, reproducible defects, feature proposals, and sensitive reports to the correct channels
• link the guide from onboarding, support, contribution, community, README, and the bug form

Validation

• pnpm docs:build
• pnpm verify:links
• issue-form YAML parse
• browser-visible acceptance at /beta-testing: active navigation, 2 tables, valid links, no horizontal overflow
• pnpm check
• staged privacy scan: no weimob, fypro, local username, or npm-token pattern

Follow-up after merge

• wait for GitHub Pages to publish the merged guide
• create the public GitHub Discussions announcement with only live links
• then close docs(beta): open external validation intake before 1.0 #37