docs: adopt MIT license

[fly1d]

Summary

• add the standard MIT License with copyright 2026 fly1d
• declare the SPDX-compatible MIT license expression in package metadata
• link the license from the README
• update security reporting text now that the repository is public

Risk classification

Low. Legal and documentation metadata only; no runtime behavior, API contract, dependency, or data change.

Evidence

• make check: 32 passed, 1 PostgreSQL integration test skipped without a database; 98.55% coverage
• wheel metadata contains License-Expression: MIT and License-File: LICENSE
• wheel includes dist-info/licenses/LICENSE
• GitHub repository visibility is public

Rollback

Revert this commit before distributing a release under MIT. Existing copies received under the MIT License cannot have those permissions retroactively revoked.

[fly1d]

Final review completed. The repository owner explicitly selected the MIT License in the controlling project task on 2026-08-12.

Verified:

• license text is the standard MIT template with copyright 2026 fly1d
• package metadata emits License-Expression: MIT and includes the license file in the wheel
• README and public-repository security reporting text are consistent
• all required CI checks passed

No unresolved findings remain. This comment records the owner's explicit license decision; the author cannot submit a GitHub approval review on their own pull request.