docs(AGENTS.md): add profile commands (save/load/delete/list) — these CLI commands exist in code but were missing from documentation, causing agent confusion when user requested 'rgb save'

AGENTS.md

@@ -27,6 +27,10 @@ qmk-rgb rgb mode <index>           # Raw zone-specific effect ID
 qmk-rgb rgb enable
 qmk-rgb rgb disable
 qmk-rgb rgb info
+qmk-rgb rgb save <name>        # Save current RGB state to a profile
+qmk-rgb rgb load <name>        # Load a profile and apply it to the keyboard
+qmk-rgb rgb delete <name>      # Delete a saved profile
+qmk-rgb rgb list               # List saved profiles
 ```
 
 `rgb` has a persistent `--zone` flag accepting `logo`, `backlight`, or `side`.