Documentation only. No behaviour, no signature and no return value changed.

g2g_extract_trips() and g2g_extract_trips_and_stop_times() no longer claim to
read CSV files - both accept a data.frame or a path, as their own @param always
said - and both are expanded to the depth the package's smaller helpers already
had. g2g_data_stops and g2g_data_terminals now state the Kandy, Sri Lanka
provenance that g2g_data_gps states. Titles are sentence case throughout.

testthat 533 pass, 0 fail, 1 skip with the Rust backend from a clean detached
clone (job 15257809), unchanged. R CMD check --no-manual retains only the
pre-existing eval_* data.table NSE note (job 15257788); all Rd checks OK.