Add `in:<N>`, `out:<N>`, and `tokens:<N>` filter fields (with `:`, `>`, `<`
operators) to the TUI filter query language. Populate input_tokens and
output_tokens on SessionListItem from the DB sessions table, wire them into
the SessionRow trait, and update the help modal to document the new fields.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Also close claudbg-4g3l, claudbg-ltt0, claudbg-37cj as already implemented.
Fixes pre-existing fmt issues in agents.rs, sessions.rs, filter.rs, and TUI files.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>