- README.md: 324 -> 106 lines, clickable TOC, quick start, formats
table, full check suite + CI; flags/env/YAML reference moved to docs
- docs/USER_GUIDE.md: new user guide (install, periods, users, export,
email, monthly --commit cycle, 21-flag reference, troubleshooting)
- docs/CONFIG.md: clickable TOC + accuracy fixes verified against code
(dedup logic was described backwards, missing report section in
--init-config, conditional STARTTLS, full --config-path role,
datetime --date ranges, --config override nuance, comment loss on
--commit, default_to without default_from is ignored)
- client.py: dedup docstring/comment now match actual behavior
