fix(#683): claw skills remove/add/uninstall/delete emits typed error, exit 1

- Add unsupported skills action guard in parse_args for remove/add/uninstall/delete
- Add unsupported_skills_action to classify_error_kind for structured JSON errors
- Fix pre-existing compile errors (stale retry_after field, missing Team variant)
- Add regression test unsupported_skills_actions_return_typed_error_683

rust/crates/commands/src/lib.rs

@@ -1180,6 +1180,9 @@ pub enum SlashCommand {
         count: Option<String>,
     },
     Unknown(String),
+    Team {
+        action: Option<String>,
+    },
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -1277,6 +1280,7 @@ impl SlashCommand {
             Self::Tag { .. } => "/tag",
             Self::OutputStyle { .. } => "/output-style",
             Self::AddDir { .. } => "/add-dir",
+            Self::Team { .. } => "/team",
             Self::Sandbox => "/sandbox",
             Self::Mcp { .. } => "/mcp",
             Self::Export { .. } => "/export",
@@ -4312,6 +4316,7 @@ pub fn handle_slash_command(
         | SlashCommand::OutputStyle { .. }
         | SlashCommand::AddDir { .. }
         | SlashCommand::History { .. }
+        | SlashCommand::Team { .. }
         | SlashCommand::Unknown(_) => None,
     }
 }