Waveform capture comparisons: always state settled vs event mode

When comparing a custom simulation-capture backend with FSDB/VCD dumps, or two custom captures with each other, say which value semantics each uses. 'Settled' capture records only the last value at each timestamp, which is what many dumpers do by default. 'Event' capture keeps every change within a timestep, including delta-cycle glitches. The two give different event counts and different file sizes on the same run, and an exact-equivalence check between a settled and an event capture fails for reasons that have nothing to do with bugs. Pin the mode in every benchmark row and equivalence gate, keep one fixed signal set as the exact-match reference, and never collapse glitches silently in an event-retaining mode.