fix(cli): surface session_id in /status JSON output

When running claw --output-format json --resume <session> /status, the
JSON output had 'session' (full file path) but no 'session_id' field,
making it impossible for scripts to extract the loaded session ID.

Now extracts the session-id directory component from the session path
(e.g. .claw/sessions/<session-id>/session-xxx.jsonl → session-id)
and includes it as 'session_id' in the JSON status envelope.

159 CLI tests pass, fmt clean.

Author: code-yeongyu

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

@@ -4825,6 +4825,11 @@ fn status_json_value(
             "unstaged_files": context.git_summary.unstaged_files,
             "untracked_files": context.git_summary.untracked_files,
             "session": context.session_path.as_ref().map_or_else(|| "live-repl".to_string(), |path| path.display().to_string()),
+            "session_id": context.session_path.as_ref().and_then(|path| {
+                // Session files live under .claw/sessions/<session-id>/<file>.jsonl
+                // Extract the session-id directory component.
+                path.parent().and_then(|p| p.file_name()).map(|n| n.to_string_lossy().into_owned())
+            }),
             "loaded_config_files": context.loaded_config_files,
             "discovered_config_files": context.discovered_config_files,
             "memory_file_count": context.memory_file_count,