john-okeefe 8fc3712cfb fix: correct ISBN normalization test expectations ...

Fix test expectations to match correct ISBN-13 checksum calculations:

- ISBN-10 "0123456789" converts to ISBN-13 "9780123456786" (not 9780123456789)
- ISBN-10 "0-12345-678-X" converts to ISBN-13 "9780123456786" (ISBN-13 never contains X)
- ISBN-10 "0306406152-" converts to ISBN-13 "9780306406157" (correct checksum)

Remove invalid test cases:
- "empty string converts to empty string" - API returns nil, not empty string
- "ISBN-13 preserves X" - ISBN-13 format never contains X character

All ISBN normalization tests now pass.

2026-02-11 17:18:00 -05:00

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server

fix: correct ISBN normalization test expectations

2026-02-11 17:18:00 -05:00