feat(landing): Pino logger guide - #1573

🟢 Confidence 8/10 · likely safe to merge. Held at 8 because earlier reviews of this pull request found 1 defect.
_{2 notes · tests not needed · risk low · 1 defect fixed in earlier rounds}

Adds the Pino logger guide at /guides/pino-logger, its three screenshots, an index entry, llms.txt coverage and an InstallTabs component for package-manager commands. Content-only; the two open findings still stand at this head.

• pino-logger.astro adds the guide with Node, Express and Fastify snippets
• InstallTabs.astro renders npm/pnpm/bun switchers using guide-highlight
• guide-highlight gains javascript, json and shell; guides index and llms.txt list the page

Before merge

• Env var · Set LOG_LEVEL in every environment, or confirm its default · apps/landing/src/pages/guides/pino-logger.astro:82

Still open from earlier reviews

• 🔵 Note · F2 · InstallTabs hardcodes the storage key installVariants returns · apps/landing/src/components/docs/InstallTabs.astro:15
• 🔵 Note · F3 · errorTiers first tier charges 3.07x Team, not "twice the Team rate" · apps/landing/src/pages/guides/sentry-pricing.astro:324

Production impact

_{c72b723 · Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}