feat: migrate frontend to Vue and Vite

[lagrangee]

Problem

The Workout frontend was a monolithic native-JavaScript surface without a component framework, production bundling, browser-level release gate, or a GitHub-to-Cloudflare main deployment workflow.

Summary

• migrate Today, Calendar, Records, Settings, and Session execution to Vue 3 + Vite + TypeScript
• preserve the Worker/API boundary while fixing export-size, environment, and terminal Session-correction edge cases found during migration
• replace legacy browser fixtures with Vue component tests, interface tests, and a real Chromium smoke journey
• build a deterministic dist inventory and add a pinned GitHub Actions production workflow for main
• add fail-closed Cloudflare preflight, ignored production config generation, and exact post-deploy revision acceptance
• remove the obsolete public prototype and legacy application bundle; retain prototype provenance in .scratch/workout-tracker-mvp/prototypes/README.md

Contract impact

• /healthz now returns the deployed 40-character Git revision in addition to service readiness
• no D1 migration is added or modified
• existing private and Coach API boundaries remain versioned and credential-protected
• production bindings are generated from committed placeholders; no production identifiers or credentials are committed

Verification

• fnm exec --using=22 npm run release-check
• fnm exec --using=22 npm run test:coverage
• fnm exec --using=22 npm run docs:lint
• fnm exec --using=22 npm run source:acceptance
• fnm exec --using=22 npm run audit:runtime
• fnm exec --using=22 npm run audit:development
• real Chromium smoke journey
• in-app browser QA for the Today and Calendar surfaces
• git diff --check

[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 2026-08-29T15:45:40.033992Z	b5bc1dd	PR opened

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