Resolve the historical GPL/ISC licensing conflict #4

Historical selected-branch GPL and published ISC/MIT disclosures conflicted. On 2026-10-13 the owner explicitly selected ISC and confirmed authority to license all included code under ISC.

• Owner documents the intended license and confirms rights for the included code.
• Authorized LICENSE, package/lock metadata and documentation now consistently declare ISC.
• Decision and migration implications are recorded in docs/RELEASE.md and docs/MIGRATION.md.

Implementation: cf4348b, PR #18. Final archive license disclosure was inspected before publication. Historical licensing evidence is retained in the documentation and Git history.