The detail page was hard-coding GHz formatting, so 50/144/222/432/902
rendered as 0.1/0.4/0.9 GHz instead of the MHz labels every amateur
operator actually uses. Switch to MHz when band < 1000, keep GHz for
microwave bands.
Also surface band and mode in the header subtitle so the key QSO
metadata is visible before SRTM/terrain enrichment completes (the
elevation-profile block that previously rendered them is gated on
that enrichment).