fix(colibri): add ListSkills + RegisterSkill to Command enum (Hermes)

The colibri CLI's parse_args and run handler referenced Command::ListSkills
and Command::RegisterSkill, but both variants were missing from the enum
definition. This caused a build failure on Linux (rustc 1.95.0).

Added the missing variants with their fields (name, description, category
for RegisterSkill). Build + test + format gate verified green.

Co-Authored-By: Hermes Agent <hermes@clawdie.si>

crates/colibri-client/src/bin/colibri.rs

@@ -42,6 +42,12 @@ enum Command {
         description: Option<String>,
         capabilities: Vec<String>,
     },
+    ListSkills,
+    RegisterSkill {
+        name: String,
+        description: Option<String>,
+        category: Option<String>,
+    },
 }
 
 fn default_socket_path() -> PathBuf {