docs: RE-confirm force-resend leaf-index numbering via EncodeField

EncodeField (0x4334e0) assigns each field's flat index via a per-leaf counter that
increments in record-walk DFS order over *(serializer+0x30) (stride 0x2e, descending
embedded) — exactly ForceResend.WalkLeaves. So the index<->name map matches the
snapshot/CalcDelta index space for standard fields; only polymorphic/dynamic-array
fields (fieldInfo flag +0xD0 &0x40) remain an edge. Removes the main verify-point.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>