Function saveMode

src/utils/sessionStorage.ts:3059–3061

(mode: 'coordinator' | 'normal')

 * Cache-only here to avoid creating metadata-only session files at startup.
 */
export function saveMode(mode: 'coordinator' | 'normal'): void {
  getProject().currentSessionMode = mode
}

/**
 * Record the session's worktree state for --resume. Written to disk by