CellGuard: LTE/5G-NR lock + IMSI-catcher detection KSU module

- cgcap.ko: cpif CP-frame capture via kprobe/kallsyms, stock-GKI build
- ratlock.sh: hold modem to LTE+NR(5G), block 2G/3G downgrade
- cgdetect.sh: always-on behavioral cell-site-simulator detection
- cgctl.sh + WebUI: block/detect toggles, status + alerts
- build-stock-gki.sh: reproducible stock-GKI module build pipeline

common/kmod/Makefile

@@ -0,0 +1,27 @@
+# CellGuard kernel module
+#
+# Cross-compile against the rango (Pixel 10 Pro Fold, Tensor G5) kernel.
+# Expects KDIR pointing at a prepared kernel tree (6.6.x).
+#
+#   export KDIR=/home/snake/RadioControl/build/rango-kernel
+#   export CROSS_COMPILE=aarch64-linux-gnu-
+#   export ARCH=arm64
+#   make
+#
+# Output: cellguard.ko
+#
+# If KDIR is unset, falls back to the running kernel's build dir
+# (only useful on a dev machine for sanity-compile).
+
+obj-m += cellguard.o
+
+KDIR ?= /lib/modules/$(shell uname -r)/build
+
+all:
+	$(MAKE) -C $(KDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+
+install:
+	@echo "Copy cellguard.ko to device then 'insmod cellguard.ko'"