Feature Request: Add sentence movement () to vim mode

Currently, Claude Code's vim mode doesn't support sentence movement shortcuts:

• ( - move backward one sentence
• ) - move forward one sentence

These are common navigation commands in vim for editing prose and longer text. They would be valuable additions to the vim mode subset, especially when composing longer prompts or editing multi-paragraph text.

'f.' and 'F.' are workable replacements, but are less convenient.