release: prepare v0.2.3 support docs-only patch

[CoderDeltaLAN]

Summary:

• Prepares v0.2.3 as a documentation-only patch release.
• Syncs SUPPORT.md with the current v0.2.3 GitHub Release and PyPI package state.
• Updates package metadata, README, SECURITY.md, and CHANGELOG release references to v0.2.3.

Validation:

• Local checks passed: 118 tests, Ruff, text hygiene, Git whitespace.
• Built wheel and sdist for 0.2.3.
• Twine check passed.
• Clean wheel install smoke passed.
• Stale public-truth guards passed.

Scope:

• Release metadata and documentation only.
• No runtime behavior changes.