New check_jtag_chain(System*): collects TAP pins by PinSpec.function, resolves
each to its net, and flags JtagTapIncomplete (a device missing TDI/TDO/TMS/
TCK), JtagBusUnbridged (TMS or TCK not common to every TAP device), and
JtagChainBreak (dangling TDO/TDI, chain fan-out, or not a single head->tail
daisy chain). Surfaced as a pass in `verify`; AnomalyKind extended. Covered by
test_bsdl_check (healthy chain, broken chain + split bus, incomplete TAP).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
New bsdl_check.{hpp,cpp}: check_pin_specs(System*) walks the nets and uses
each pin's PinSpec direction/function to flag DriveContention (>=2 push-pull
output drivers), UndrivenNet (a multi-pin net with input(s) but no driver),
and NcWired (a no-connect pin wired onto a multi-pin net). Added as a pass in
`verify`; AnomalyKind extended accordingly. Nets with no direction data are
skipped, so un-modelled parts produce no noise. Covered by test_bsdl_check.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
