Rename rbos → redbear everywhere, add redbear-info system tool

Replace all 'rbos'/'RBOS' references with 'redbear'/'Red Bear OS'
across the build system, scripts, docs, and configs. Renamed files:
  rbos.ipxe → redbear.ipxe
  assets/rbos-icon.png → assets/redbear-icon.png
  recipes/system/rbos-info → recipes/system/redbear-info

Added redbear-info: a system tool that enumerates all Red Bear OS
custom components, checks runtime availability via scheme paths and
binary presence, and prints status/test info. Supports --verbose,
--json, and --test output modes. Zero external dependencies.

scripts/network-boot.sh

@@ -9,7 +9,7 @@ set -ex
 trap 'kill -HUP 0' EXIT
 
 eval $(make setenv)
-make "${BUILD}/rbos-live.iso"
+make "${BUILD}/redbear-live.iso"
 
 echo "Allowing packet forwarding"
 echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward
@@ -45,7 +45,7 @@ ARGS=(
     "--dhcp-boot=tag:!ipxe,tag:efi-aarch64,ipxe-aarch64.efi"
     # IPXE
     "--dhcp-userclass=set:ipxe,iPXE"
-    "--dhcp-boot=tag:ipxe,rbos.ipxe"
+    "--dhcp-boot=tag:ipxe,redbear.ipxe"
 )
 
 sudo dnsmasq "${ARGS[@]}"&