Map FSDB public IDs to reconstruction nodes with fsdbdebug -show_eifn

Found a practical mapping in Verdi W-2024.09 advertised CLI options: fsdbdebug -top_n_var 0 -with_computed_signal -show_eifn file.fsdb prints public ID/name plus Ei,Cg,Fn. Comparing with -top_n_var 0 without -with_computed_signal separates reported stored and computed signals. Verified on 12 controlled cases: aliases/combinational expressions computed; independently driven, flop, latch and constant outputs stored. Declaration reordering changes public IDs without changing internal node indices; driver swaps change the input-node mapping correctly. For tested Ei=0,Cg=-1 records, Fn indexes the raw reconstruction node array. After expanding run-length encoded scalar widths and masking width flags, 4,718 named-signal widths matched across two real dumps with zero mismatches; 95 hidden rows lacked public widths. Preserve the full tuple and one-to-many name mappings. Do not treat Cg=0/Fn=0 as a shared alias, or infer dependency edges/RHS operators from this mapping alone. Using -load_range bounded inclusive loading, but printed counts were not exact point-window counts. Guard version-dependent CLI parsing; unreported signals remain unknown.