Rule (Stage 0, pre-launch): clear the technical gates or stay invisible — 200, robots.txt not blocking JS/CSS, scan for stray `noindex`, real `<a href>` links, SSR/SSG for indexable content, responsive design for mobile parity

Rule: Stage 0 — pre-launch / launch week. Clear the gates or stay invisible. Non-negotiable checklist:

1. Confirm pages return 200 (Google hard gate — only 200-status pages are queued for rendering; non-200 (4xx/5xx) may skip rendering entirely).
2. Confirm robots.txt does not block the site or its JS/CSS (Google hard gate — robots.txt Disallow blocks crawling AND blocks rendering of JS/CSS; "Google Search won't render JavaScript from blocked files or on blocked pages").
3. Scan for a stray noindex in meta, X-Robots-Tag, and the CMS toggle (Rule: scan for a stray noindex BEFORE launch — meta tag, X-Robots-Tag header, CMS "discourage search engines" toggle — the most common launch-killer). Most common launch-killer.
4. Ensure all important navigation uses real <a href> links, not onclick/buttons (Rule: use real <a href> HTML links for any navigation Google must follow — NOT onclick, NOT <button>, NOT javascript:void(0); let the SPA router intercept the click rather than replacing the anchor).
5. Choose SSR or SSG for any content that must be indexed (Rule: SSR or SSG is the DEFAULT for any content that must be indexed; CSR for indexable content is a GAMBLE whose downside lands hardest on new low-authority sites).
6. Use responsive design for automatic mobile parity (Rule: mobile parity is MANDATORY — anything missing on mobile (content, links, structured data, metadata) is missing from Google's index; do NOT trim the mobile version, Responsive design (same HTML/URL across devices) is Google's recommended defense — eliminates mobile/desktop parity gaps by CONSTRUCTION; classic failure mode is a separate or aggressively-trimmed mobile template).

Why: Gates are binary and unforgiving. The pre-launch hygiene check costs minutes and prevents weeks of "why isn't Google seeing us." Pairs with the lifecycle brief's Rule (Stage A, pre-launch / launch week): remove the gates — verify GSC, submit honest sitemap, request homepage indexing, confirm robots.txt + DNS + 200/404/410 hygiene, ensure mobile/desktop parity (sitemap + GSC verify + homepage indexing request).

How to apply: Run the six checks on at least 5 representative pages before the DNS cutover. If any gate fails, fix before launching — fixing post-launch resets discovery and trust accrual.