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/AGENTS.md

@@ -45,7 +45,7 @@ git rebase upstream-redox/master
 # If rebase fails (nuclear option):
 git rebase --abort
 git reset --hard upstream-redox/master
-./local/scripts/apply-patches.sh --force     # Rebuild RBOS changes from patch files
+./local/scripts/apply-patches.sh --force     # Rebuild Red Bear OS changes from patch files
 
 # After sync:
 cargo build --release                         # Rebuild cookbook