VCS FSDB keeps [0:0] on 1-bit vectors; VCD/wellen drops it

VCS writes a 1-bit vector declared [N-1:0] with N=1 into FSDB as name[0:0], while wellen loading a VCD shows plain name. So looking signals up by RTL name works on VCD dumps and silently fails on FSDB. When no exact name matches, compare after stripping a trailing \[\d+(:\d+)?\] from the var's last segment only (never from scopes). Accept the match only when exactly one var matches, or a bit-blasted dump (foo[0], foo[1]) shows foo[0] as the whole vector.