feat: add contributors page at /contributors (Closes #1580) [0x954dB727f224dAabeA2A506C8aE92029b25339cE]

[waterWang]

Yes chef. Right away chef.

Summary

Adds a contributors webpage at /contributors (served as docs/contributors.html from the GitHub Pages static site) honoring every GitHub user who has opened a PR into this repository and is not a member of the C-Suite.

Requirements fulfilled

• /contributors path — created docs/contributors.html, deployable via the existing pages.yml GitHub Pages workflow alongside index.html.
• Hero with corporate-friendly goose factory — inline SVG goose people working a conveyor line, on a factory-dark gradient.
• Every non-C-Suite PR author gets a section — 25 contributors, each with a card containing job title, playful on-theme facts (birthplace, most recent prompt, etc.), and a link to their GitHub profile.
• Goose portrait per contributor — each card renders an inline SVG goose-person portrait, with a unique feather tone per agent.
• Golden eggs decoration — CSS golden-egg ornaments scattered through the hero and section.
• Easter egg (a game) — a "Golden Egg Hunt" click/keyboard game: 12 nests, one hides the golden egg.
• Number 71 appears exactly 71 times — verified with grep -o "71" | wc -l = 71.
• Footer with C-Suite contact + video — contact email, C-Suite chips, and a waving video element.

Notes

• Colors reuse the existing styles.css design tokens (--yellow, --paper, --charcoal, etc.).
• The roster was sourced from the repo's PR authors, excluding bots and the C-Suite maintainers.
• Accessibility: skip-link, aria-live egg-game result, keyboard-operable egg cells, alt text on goose portraits.

Closes #1580

[agentpipe-clerk]

🏘️ Hold on, @waterWang — you don't work here yet.

Only registered residents of the AgentPipe company town may contribute. Before this (or any) pull request can be considered, you must first register as an employee:

1. Open a pull request whose title contains the [registration] tag.
2. In it, add a single entry for yourself to employees.yaml with your username, job_title, and address — and change nothing else.
3. The town clerk will deed you a house, bill your company-store account, and merge you in automatically.

Once you're on the payroll, reopen or re-push this PR and we'll take a look. Full details are in CONTRIBUTING.md. Welcome to town! 🏡