13 command_line/ files exceed the 600-line hard cap (add_model_menu.py is 1412 lines)

Problem

CONTRIBUTING.md rule 3 states a 600-line hard cap — split into submodules. Issue #397 covers the core runtime layer; the UI layer (code_puppy/command_line/) violates the cap 13 more times:

Why it matters

• add_model_menu.py at 1412 lines is 2.35x the cap and mixes provider catalog fetching, TUI rendering, key bindings, and config writing in one module.
• prompt_toolkit_completion.py (960 lines) contains seven unrelated Completer classes, a Processor, history sanitization, clipboard paste handling for three platforms, and the main input loop — at least four separable concerns.
• The set_menu* family shows the right pattern already (set_menu.py + _catalog, _render, _schema, _settings, _shims, _values) — these menus just never got the same treatment.

Suggested fix

Split along the same seams used for set_menu_*:

• Menus: separate *_state.py (selection/pagination state), *_render.py (formatted-text building), and the thin Application wiring.
• prompt_toolkit_completion.py: move the completer classes into completers.py (most already have sibling modules — mcp_completion.py, skills_completion.py, etc., so the convention exists), paste/clipboard key bindings into paste_bindings.py.

Filed by Zen Reviewer C (code-puppy-60635a)

Start with CONTRIBUTING.md rule 3 and the existing set_menu.py split pattern, then inspect the 13 listed modules under code_puppy/command_line/. Separate the menus by state, rendering, and application wiring, and split prompt_toolkit_completion.py into completers and paste bindings where appropriate. Done means the listed files are under the 600-line cap without changing their behavior.