Refresh Gmail Organizer as an AI flagship

[schulerj89]

What changed

• Reworked the README around the product problem, local-first architecture, safety model, screenshots, and contributor path.
• Added MIT licensing, contribution and conduct guidance, a security policy, changelog, detailed setup documentation, issue forms, and a pull request template.
• Added Go and React CI plus Dependabot configuration.
• Updated the frontend lockfile to patched Vite/PostCSS versions and made the current no-test frontend inventory explicit.

Why

Gmail Organizer already demonstrates applied AI, product judgment, and careful security boundaries, but its repository did not make that value easy to discover or support outside participation. This packages it as the lead public AI project on the profile.

User and developer impact

Visitors get a faster product tour and clear trust model. Contributors get reproducible setup and verification steps, structured issue forms, CI, dependency updates, private security reporting guidance, and an explicit license.

Verification

• go test ./...
• go vet ./...
• cd web && npm test
• cd web && npm run build
• cd web && npm audit --audit-level=high (0 vulnerabilities)
• Secret-shaped string scan across the changed repository files