Module insert 

Phase 6.6d: insert-mode FSM body relocated from hjkl-engine::vim.

Dispatched by crate::dispatch_input before the deprecated Editor::step_input shim. The engine keeps an in-engine duplicate body in vim::step (Mode::Insert arm) for back-compat with the deprecated shim path until Phase 6.6h.

Functions

step_insert

Drive the insert-mode FSM for one keystroke.