v0.2.5

v0.2.5

• Atomic fail-closed handling for Russian four-digit leading-zero years, including contextual forms, signs, continuations, and unsupported ranges.
• One UTF-8 byte-accurate UnresolvedNumber diagnostic per preserved candidate.
• Working EN/RU quality baseline: 751 cases, 651 correct transformations, 100 justified preservations, 0 unnecessary refusals, 0 incorrect/partial results.
• Published quality archives remain unchanged.