AODBcRewriter: remap every index column an output table carries (O2-7098)

Stage 1b (added in #2370) reorders O2track_iu/O2mfttrack/O2fwdtrack to keep
the "-1" ambiguous group contiguous, but wrote each table as soon as it was
planned. O2fwdtrack references O2mfttrack (reordered later in the same loop)
and itself (fIndexFwdTracks_MatchMCHTrack); neither permutation existed yet
at write time, so both columns kept pre-reorder row numbers -- in range, so
AODBcRewriterValidate passed, while every global muon got a foreign MFT/MCH
leg (Maurice Coquet, sameParticle=0 on an anchored pO sample; patch proposal
#2418). This fires whenever Stage 1b's regroup runs, independent of any
BC/collision reorder, so every merged MC AO2D since 4 Jun is affected.

Fix:
* kIndexRefs: one registry of "which fIndex* column points at which table",
  used by the rewriter, the validator, and a new drift guard (an
  unregistered fIndex* column now fails the test instead of silently
  mis-linking data).
* buildRemaps() derives a table's full remap set from that registry; the old
  "primary index + optional extras" split in rewriteTable is gone, so a
  stage can no longer forget a column the way Stage 1b forgot O2fwdtrack's.
* Planning and writing are separate phases: every stage publishes its row
  permutation before anything is written, so forward/self references
  resolve correctly.

New AODBcRewriterCheckLinks(in, out): fingerprints each row's non-index
payload and checks, per table, that (row, referenced row) pairs survive the
rewrite -- the only check that can see this bug class, since the corrupted
indices were structurally valid. Needs only the input file, so it also runs
on real production AO2Ds.

MC/utils/tests/ adds the executable test this tool never had: a synthetic
AO2D covering every pathology (duplicate/non-monotonic BCs, duplicate MC
collisions, split -1 groups, fwd<->MFT and fwd->fwd references, ...), driven
by run_aodbcrewriter_tests.sh -- ROOT only, seconds to run, nothing binary
committed.

Verified against the pre-fix rewriter and a real anchored pp production
(run 553185, LHC24al apass1): sameParticle collapses to 0 with the shipped
code and is fully restored with this fix, in every scenario tested,
including one engineered to contain genuine duplicate BCs.

Diagnosis and original patch: Maurice Coquet (#2418).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: sawenzel