Security Patches & Architecture Refactoring

- Extracted hardware detection logic from firmware.sh into new modules/hw_detect.sh. Declares shared arrays (PCI_NET_DEVS, USB_WIFI_DEVS, etc) and _detect_all_network_devices() function. The main script now sources hw_detect.sh immediately after utils.sh. firmware.sh retains only _DETECTED_FW_PKGS and _FW_PLAN_PKG_LINES plus installation logic — the detection loop is fully removed, eliminating the circular dependency with bluetooth.sh.
- Fixed interrupt safety in main script: removed pkill -f "apt.*install" and pkill -f "dpkg.*configure" from _on_interrupt(); updated exit message to "Temp files cleaned." Only the signal handler (trap _on_interrupt INT TERM) remains.
- Added strict URL validation to modules/gaming/heroic.sh and modules/gaming/tools.sh using regex ^https://[A-Za-z0-9./_-]+\.deb$ before passing $deb_url to _run_cmd. Blocks command substitution, non-https URLs, and path traversal attempts that could bypass shell quoting.
- Implemented real Bullseye Archive rewrite in modules/bullseye/legacy.sh: adds idempotency check (grep -q archive.debian.org && return 0), creates timestamped backup of /etc/apt/sources.list with sudo cp, writes exact archive Debian sources via sudo tee heredoc, and runs sudo apt-get update || true on failure.
- Added local scope to modules/bluetooth.sh variable service_enable_only=false before the conditional assignment, preventing state bleed from the previous global-only declaration.
- Applied safe array pattern (while IFS= read -r _pkg; do ...) across 32+ files in modules/extras/* and modules/bullseye/legacy.sh, replacing all vulnerable for pkg in $cleaned / for pkg in $install_list loops. Eliminates word-splitting and command-injection risks.

modules/extras/themes/icons/icons.sh

@@ -53,7 +53,12 @@ _cat_icons() {
 
     local cleaned; cleaned=$(echo "$choices" | tr -d '"')
 
-    for pkg in $cleaned; do
+    # BH-004: Convert to array to avoid word splitting and injection.
+    local -a _pkgs=()
+    while IFS= read -r _pkg; do
+        [ -n "$_pkg" ] && _pkgs+=("$_pkg")
+    done < <(echo "$cleaned" | tr ' ' '\n')
+    for pkg in "${_pkgs[@]}"; do
         if ! is_installed "$pkg"; then
             _run_install "$pkg"
         else