Rebrand landing for security practitioners, redesign, drop toolchain

- Reposition Arcline OS as the OS for people who defend infrastructure
- Add Security Stack section (Wazuh, Suricata, ClamAV, OpenSCAP, Falco,
  gitleaks/trufflehog, syft/grype, Lynis) plus compliance-ready callout
- Reframe editions for SOC/blue-team/cloud-security audiences; add Kali
  and Security Onion comparisons; update meta/OG tags for security intent
- Remove the custom Arcline Toolchain (11 Go tools) and all references
- Redesign CSS: tactical near-black + amber palette, HUD details
  (hero grid, terminal caret + sigil, card corner brackets, status dot),
  sharpened nav/buttons, responsive fixups; both dark and light themes

static/favicon.svg

@@ -1,6 +1,6 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" width="32" height="32">
   <rect width="32" height="32" fill="#0b0c0e"/>
-  <path d="M5 27L16 5L27 27" fill="none" stroke="#0acf97" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path d="M9 20H23" fill="none" stroke="#0acf97" stroke-width="2.5" stroke-linecap="round"/>
+  <path d="M5 27L16 5L27 27" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>
+  <path d="M9 20H23" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round"/>
 </svg>