ULS was wired into AddQSO alone, so an operator who downloaded it and has no
QRZ.com/HamQTH account saw nothing while typing a US call: cty.dat gives the
country, the zones, and a 4-character grid that is the ENTITY centroid — a
thousand kilometres from the station. The county and the real square were stamped
after logging, too late to point an antenna with.
The enrichment runs last in the lookup wrapper and only fills blanks, so a
provider always wins. ULS carries no name and no address, so it completes a QRZ
record and can never replace one.
The grid needed a rule of its own. refineGrid keeps what is there unless the new
value extends it — correct for a QRZ square, wrong against an entity centroid,
which is simply a different square. A per-callsign FCC square therefore beats any
4-character grid, while a 6-character one already present is left untouched.
Lat/lon are recomputed only when we actually moved the grid.
Portable calls are skipped: W1AW/4 is not what the FCC licensed.
