DD 2.1: trim metadata whitespace + clear BuiltPre1978YN LookupStatus

Trim trailing whitespace from 5 cells (Fields Definition D321/D1207/D1514, Lookups Definition D134, Lookups StandardLookupValue B2779 'Appraiser '). Clear BuiltPre1978YN's LookupStatus (P836, was 'Open') — the field is typed Edm.Boolean and a Boolean is not an enumeration, so it should not carry a LookupStatus. Applied with openpyxl (formatting/comments/merged cells preserved); no URL canonicalization (kept the diff to just these corrections).

Addresses #211.

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

Author: darnjo