Feature/port264specs

[klngwll]

This PR strengthens Marcframe spec coverage around bib 008, 260, and 264, and improves readability by naming all 264 specs. It supersedes the old draft #1064

Improves regression protection for high-impact provisionActivity mappings and makes failures easier to interpret by using explicit scenario names. Covers edge/partial 264 input patterns that appear in real data.

Added 008 + 264 interaction coverage:

• publication place/agent/date with 008
• no publication place with 008
• publisher-only with unknown 008 date/country
• conflicting 008 year vs 264$c year (both preserved)

Strengthened direct 264 coverage:

• explicit ind2=0 (Production)
• explicit ind2=2 (Distribution)
• explicit ind2=3 with $3 (appliesTo)
• standalone ind2=4 copyright case ($c)
• partial field cases ($a only, $b only, malformed $c)
• existing multipart publication + copyright scenario retained
• Named previously unnamed 264 specs for clearer intent.

MarcFrameConverterSpec passes under Java 21