v1.15

Frequency-based transmit-VFO / split detection (the definitive relay-safety fix). The transmit VFO is derived from byte 236 bit 7 on idle frames = 'the lower-frequency VFO is the transmit VFO', matched against byte 184 (primary/displayed VFO) and byte 196 (secondary VFO) frequencies. The relays, TX log and ic905/tx sequence the band of whichever VFO actually transmits. Verified on-air across every primary/secondary choice AND with the two bands swapped onto opposite VFOs — it tracks frequency order, not the VFO A/B slot. Supersedes the v1.10-v1.14 attempts that treated byte 236 bit 7 as a fixed split flag.

Known issue: with both VFOs on the same band + split enabled, the reported TX frequency may show the other VFO's frequency (byte 236 distinguishes the transmit band, not which of two same-band VFOs). Relay band/sequencing is unaffected and always correct; only the displayed frequency can be off in that case.