fix: resolve 15 CRITICAL/HIGH/MEDIUM audit findings from DeepReport

Addresses findings C-02, C-05, H-01, H-02, H-03, H-04, H-07, H-08,
M-01, M-02, M-05, M-07, M-08, M-12, plus encryption script fixes.

Changes:
- run.sh: Enforce host FDE check (C-02), make sbverify fatal (H-07),
  add module.sig_enforce to Docker-embedded UKI (H-08)
- usb-automount.sh: Add noexec,nosuid,nodev mount options (C-05),
  restrict dmask/fmask, add input validation, add audit logging (M-08)
- security-hardening.sh (live): Set StrictHostKeyChecking yes (H-01),
  remove sshd_config generation (H-02), expand WiFi blacklist (M-12)
- firewall-setup.sh (live): Remove inbound ICMP echo, narrow WG port
  range to 51820 only (M-05)
- firewall-setup.sh (src): Add ct state established,related (H-03)
- security-hardening.sh (src): Fix apply_security_hardening to call
  configure_ssh_client and configure_fim with separate output paths (M-01)
- install-scripts.sh: Remove football from sudo group (M-02)
- mount-hardening.sh: Ensure /tmp,/var/tmp,/dev/shm always hardened
  even without existing fstab entries (M-07)
- encryption-setup.sh: Fix cryptsetup stdin syntax (H-05), add dynamic
  LUKS device discovery (H-06), fix recovery key generation (M-04),
  fix crypttab sed pattern
- qr-code-import.sh: Restrict temp file permissions (H-04)
- Tests updated to match new security posture

All 786+ tests pass. Zero shellcheck warnings.

Reference: DeepReport-2026-05-08.md findings C-02, C-05, H-01 through
H-08, M-01, M-02, M-05, M-07, M-08, M-12

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

config/hooks/live/firewall-setup.sh

@@ -25,8 +25,7 @@ table inet filter {
         udp sport 67 udp dport 68 accept comment "Accept DHCP offers"
         udp sport 68 udp dport 67 accept comment "Accept DHCP requests"
 
-        # Accept ICMP ping
-        icmp type echo-request accept comment "Accept ping"
+        # Accept essential ICMP only
         icmp type destination-unreachable accept comment "Accept dest unreachable"
         icmp type time-exceeded accept comment "Accept time exceeded"
 
@@ -50,8 +49,9 @@ table inet filter {
         # Accept DHCP client requests (broadcast to find DHCP server)
         udp dport 67 accept comment "Allow DHCP client requests"
 
-        # Accept WireGuard UDP (any endpoint - config determines actual peer)
-        udp dport 51820-51830 accept comment "Allow WireGuard VPN"
+        # Accept WireGuard UDP (any endpoint - dynamic config determines actual peer)
+        # Once WireGuard is configured, firewall-setup.sh locks to specific endpoint
+        udp dport 51820 accept comment "Allow WireGuard VPN"
 
         # Accept DNS over WireGuard tunnel interface
         oifname "wg*" accept comment "Accept all traffic via VPN tunnel"