claude-sessions spawn: add --headless/--create for non-interactive use

Claude-Session: https://claude.ai/code/session_01JXneLTuvb5Gxim3DTN2tQa

memory/script-claude-sessions.md

@@ -16,6 +16,10 @@ Python script (`scripts/claude-sessions`, symlinked to `~/sbin/`). Manages Claud
 - **Folder browser.** `zenity --file-selection --directory` when `DISPLAY`/`WAYLAND_DISPLAY` is set and zenity exists (has Create Folder). Otherwise a terminal browser: number = open, `u` up, `n` new folder, `/text` filter, `>` `<` page, `h` hidden, `~`/`/path` jump, Enter/`s` select, `q` cancel.
 - **Topic.** Becomes the tmux session name and the Remote Control name (passed as `--name` to `claude-tmux`). Defaults to the Title-Cased folder name. If that name is already a live tmux session, no default is offered and a unique topic is required. Topics containing `.` or `:` are rejected because tmux rewrites them to `_`.
 
+## Headless spawn
+
+`claude-sessions spawn <folder> --headless [--name topic] [--create] [--mode m] [--profile p]` — no prompts, no attach, for scripts and the `/spawn-session` skill. Exit 1 = folder missing (or `--create` needs an absolute path); exit 2 = topic in use (default topic is the Title-Cased folder name; no `#N` suffix is added). Without `--headless`, `spawn` behaves as before.
+
 ## Gotchas
 
 - "In use" means a live tmux session. Resumable registry entries do not block a topic.