feat(marketing): add ZeroTier Network Governance page and content

Add comprehensive marketing content for ZeroTier Network Governance feature
including a dedicated landing page, navigation updates, and feature highlights
across the homepage and features page.

- Add new ZeroTierPage with feature documentation and use cases
- Add ZeroTier to navigation in MarketingLayout header and footer
- Update HomePage hero headline and add ZeroTier feature section
- Add ZeroTier features section to FeaturesPage
- Add ScrollToTop component for better navigation UX
- Move ApiDevTools to AuthenticatedLayout (dev mode only)
- Add SSR tests for marketing pages
- Update SSHCertificatesPage comparison table for clarity
- Add documentation link to MarketingLayout footer

src/pages/marketing/SSHCertificatesPage.tsx

@@ -68,14 +68,14 @@ code: "# Certificate auto-expires",
 ];
 
 const comparisonFeatures = [
-{ feature: "Lifetime", static: "Permanent", cert: "Minutes to hours" },
-{ feature: "Rotation", static: "Manual, error-prone", cert: "Automatic" },
-{ feature: "Auditability", static: "None", cert: "Full chain of custody" },
-{ feature: "Revocation", static: "Distribute to all servers", cert: "Disable user" },
-{ feature: "Access Control", static: "Manual key distribution", cert: "Group-based policies" },
-{ feature: "Identity Link", static: "Anonymous", cert: "Verified identity" },
-{ feature: "Onboarding", static: "Copy keys manually", cert: "Self-service" },
-{ feature: "Offboarding", static: "Hunt and remove keys", cert: "Instant revocation" },
+  { feature: "Key Lifetime", static: "Permanent — keys never expire", cert: "Minutes to hours — auto-expiration" },
+  { feature: "Key Rotation", static: "Manual process, error-prone", cert: "Automatic with each certificate" },
+  { feature: "Audit Trail", static: "No visibility into usage", cert: "Full chain of custody logged" },
+  { feature: "Revocation", static: "Must reach all servers manually", cert: "Disable user — instant globally" },
+  { feature: "Access Control", static: "Manual key distribution to servers", cert: "Group-based policies, self-service" },
+  { feature: "Identity Link", static: "Anonymous — no user verification", cert: "Tied to verified corporate identity" },
+  { feature: "Onboarding", static: "Admin copies keys to every server", cert: "User registers key once, self-service" },
+  { feature: "Offboarding", static: "Hunt and remove keys from servers", cert: "Disable user — all certs invalidated" },
 ];
 
 const useCases = [