Broadcom, Utils & Headless Fixes

- Removed dead Broadcom hardware IDs (4357/4358/4360/4727) from `_is_broadcom_b43`, retaining only valid ID 4352 to eliminate false positives in the case statement.
- Added a guard in `_handle_wireless` Level 3 to verify `linux-headers` availability via `apt-cache policy`. Skips DKMS compilation if headers are missing, preventing transaction failures during installation.
- Implemented Broadcom combo card detection (WiFi + Bluetooth) by scanning `PCI_BT_DEVS`. Automatically writes `/etc/modprobe.d/broadcom-combo.conf` with `softdep wl post: btusb` and warns users about potential reboot requirements.
- Enhanced Level 2 (`firmware-b43-installer`) with post-installation validation for `/lib/firmware/b43`. Provides clear recovery instructions via `sudo dpkg-reconfigure firmware-b43-installer` if the directory is empty or missing after installation.
- Created a new helper `_msg_red()` in `utils.sh` to handle critical error messages with colored Whiptail output, replacing standard alerts for migration warnings and failures.
- Updated `repos/migrate.sh` to use `_msg_red()` for branch migration warnings and failure states, ensuring visibility of critical issues while keeping completion messages informative.
- Verified headless mode guards across 16 separate extras files (`office.sh`, `fetch.sh`, `cursors.sh`, etc.), preventing unnecessary package installations on servers without display environments.
- Completed syntax verification (`bash -n`) across all core and extra modules, ensuring no errors in the updated logic for firmware, gaming, swap, or repository management scripts.
- update readme.md

modules/extras/system/software_centers.sh

@@ -1,6 +1,12 @@
 # software_centers.sh — Standalone Software Center installer
 
 _cat_software_centers() {
+    local headless=false
+    _is_headless && headless=true
+    if $headless; then
+        echo "Software centers require a GUI — skipping."
+        return
+    fi
     local de_type
     de_type=$(_detect_desktop_type)
     local sc_choice