fix(gamedata): drop EncodeField refs.strings (FindString can't match long %d-format strings)

ModSharp logs 'Failed to find String "...encoder wrote %d bits"' then falls
back to the sig. The anchor was pure noise (length cap on format strings, same
as WriteDeltaEntity). Byte sig is the sole reliable resolver; kept.

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