fix: support /plugins slash command in resume mode (#2973)

* fix: support /plugins slash command in resume mode

Move SlashCommand::Plugins out of the 'unsupported resumed slash
command' catch-all and add a handler arm in run_resume_command that
calls handle_plugins_slash_command for list/help actions.

Mutation actions (install/uninstall/enable/disable) are rejected with
a clear error since there is no runtime to reload in resume mode.

Add /plugins coverage to resumed_inventory_commands test in
output_format_contract.rs: kind, action, reload_runtime, target.

Before: claw --resume session.jsonl /plugins --output-format json
-> {error: 'unsupported resumed slash command', type: 'error'}, exit 1

After: claw --resume session.jsonl /plugins --output-format json
-> {kind: 'plugin', action: 'list', ...}, exit 0

* style: cargo fmt line wrap in run_resume_command plugins handler

* fix: block /plugins update in resume mode, fix comment

Address REQUEST_CHANGES from OMX review:
1. Add 'update' to the blocked mutation actions in resume mode
   (previously only install/uninstall/enable/disable were blocked)
2. Fix comment: 'Only list is supported' instead of 'Only list/help'
   since /plugins help doesn't actually parse as a valid action

* style: cargo fmt after conflict resolution

rust/crates/rusty-claude-cli/src/main.rs

@@ -3545,6 +3545,37 @@ fn run_resume_command(
                 json: Some(handle_skills_slash_command_json(args.as_deref(), &cwd)?),
             })
         }
+        SlashCommand::Plugins { action, target } => {
+            // Only list is supported in resume mode (no runtime to reload)
+            match action.as_deref() {
+                Some("install") | Some("uninstall") | Some("enable") | Some("disable")
+                | Some("update") => {
+                    return Err(
+                        "resumed /plugins mutations are interactive-only; start `claw` and run `/plugins` in the REPL".into(),
+                    );
+                }
+                _ => {}
+            }
+            let cwd = env::current_dir()?;
+            let loader = ConfigLoader::default_for(&cwd);
+            let runtime_config = loader.load()?;
+            let mut manager = build_plugin_manager(&cwd, &loader, &runtime_config);
+            let result =
+                handle_plugins_slash_command(action.as_deref(), target.as_deref(), &mut manager)?;
+            let action_str = action.as_deref().unwrap_or("list");
+            let json = serde_json::json!({
+                "kind": "plugin",
+                "action": action_str,
+                "target": target,
+                "message": &result.message,
+                "reload_runtime": result.reload_runtime,
+            });
+            Ok(ResumeCommandOutcome {
+                session: session.clone(),
+                message: Some(result.message),
+                json: Some(json),
+            })
+        }
         SlashCommand::Doctor => {
             let report = render_doctor_report()?;
             Ok(ResumeCommandOutcome {
@@ -3631,7 +3662,6 @@ fn run_resume_command(
         | SlashCommand::Model { .. }
         | SlashCommand::Permissions { .. }
         | SlashCommand::Session { .. }
-        | SlashCommand::Plugins { .. }
         | SlashCommand::Login
         | SlashCommand::Logout
         | SlashCommand::Vim

rust/crates/rusty-claude-cli/tests/output_format_contract.rs

@@ -397,6 +397,34 @@ fn resumed_inventory_commands_emit_structured_json_when_requested() {
         agents["count"].is_number(),
         "count must be a number, not a text render"
     );
+
+    let plugins = assert_json_command_with_env(
+        &root,
+        &[
+            "--output-format",
+            "json",
+            "--resume",
+            session_path.to_str().expect("utf8 session path"),
+            "/plugins",
+        ],
+        &[
+            (
+                "CLAW_CONFIG_HOME",
+                config_home.to_str().expect("utf8 config home"),
+            ),
+            ("HOME", home.to_str().expect("utf8 home")),
+        ],
+    );
+    assert_eq!(plugins["kind"], "plugin");
+    assert_eq!(plugins["action"], "list");
+    assert!(
+        plugins["reload_runtime"].is_boolean(),
+        "plugins reload_runtime should be a boolean"
+    );
+    assert!(
+        plugins["target"].is_null(),
+        "plugins target should be null when no plugin is targeted"
+    );
 }
 
 #[test]