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.

local/scripts/test-baremetal.sh

@@ -186,7 +186,7 @@ refuse_unsafe_device "$DEVICE"
 warn_if_system_disk "$DEVICE"
 
 if [ "$SKIP_BUILD" -eq 0 ]; then
-    echo "=== Building RBOS image ==="
+    echo "=== Building Red Bear OS image ==="
     run_cmd make -C "$REDOX_ROOT" all CONFIG_NAME="$CONFIG"
 else
     echo "=== Skipping build step ==="
@@ -194,7 +194,7 @@ fi
 
 echo "=== Checking image ==="
 if [ ! -f "$IMAGE_PATH" ]; then
-    echo "ERROR: RBOS image not found: $IMAGE_PATH"
+    echo "ERROR: Red Bear OS image not found: $IMAGE_PATH"
     exit 1
 fi