- pcap.py: _parse_tsresol now pads options to a 32-bit boundary
((-length) % 4) and uses 2** for the MSB-set (power-of-2) case, so
nanosecond if_tsresol is read correctly (was defaulting to µs and
scaling timestamps 1000x)
- database/server: set imported session started/ended from the first/last
packet timestamps (falling back to wall-clock for synthetic SPB)
- frontend: formatDuration renders hours
- tests: tsresol (ns after padded option, default µs, ns round-trip) and
session-window/fallback (119 total)