feat: add journal submission kits + paper scaffold; restructure package

- init journal <elsevier|ieee|springer>: self-contained, make-buildable kits
  (Springer sn-jnl.cls + bst bundled; reuses project references.bib)
- init paper scaffold: ctexart + Fandol fonts, bib at root, latexdiff highlighted
- move templates/ under mytoolkit/, add info/references, relocate protocols
- migrate mytoolkit skill into submodule; update README/CLAUDE docs

mytoolkit/api/voice.py

@@ -32,7 +32,7 @@ def synthesize_tts(
     Returns absolute path to the output audio file.
     """
     # Delayed import to avoid circular dependency when bin.commands is not yet loaded
-    from mytoolkit.commands.protocols import EventType, MsgType, full_client_request, receive_message
+    from mytoolkit.protocols import EventType, MsgType, full_client_request, receive_message
 
     try:
         import websockets