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

main.go

@@ -163,7 +163,7 @@ func handleIndex(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	data := map[string]interface{}{
-		"Title": "Arcline Project",
+		"Title": "Arcline OS — Hardened Linux for Security Practitioners",
 	}
 	if err := templates["index"].ExecuteTemplate(w, "base", data); err != nil {
 		log.Printf("render error: %v", err)