docs: reconcile published release history and unreleased maintenance notes - #149

Closes #148

Changes

Reconcile release/changelog.json with verified publication records and regenerate CHANGELOG using the existing generator. The current generated file still labels 0.1.0 as unreleased and omits the published patch history.

• Correct 0.1.0 to its verified 2026-08-09 publication date. Its existing history is otherwise preserved; the source content matches the original v0.1.0 tag.
• Add concise patch summaries and links to their actual published release notes through 0.1.12, using matching GitHub/PyPI dates.
• Identify 0.1.2 as an annotated tag dated 2026-08-11, with no matching current publication record. Do not claim it was never published or invent a removal history.
• Record the accepted numerical, dependency, guide, workflow and contributor changes under explicitly unreleased 0.1.13 notes, including the nonfinite-CAGR and target-rounding compatibility limits.

The historical compatibility test now requires its original records to remain present while allowing additional release entries. Its previous exact-set assertion prevented any later release from being documented. The earlier beta history is preserved.

Verification

At base 082c6a0 with the corrected real release-history input, the old test failed on valid additional versions. At fix 8d8d0c7, all four focused tests passed. Removing the required 0.1.0 compatibility record through the actual JSON/generator pipeline still failed the corrected test; restoring the source returned all four tests to passing.

Selected head d94b6ec incorporates accepted main e349cbf and adds the now-merged policy/migration notes. Generator write/check, four focused tests, strict MkDocs, rendered links, all hooks and diff checks pass. Normal source push and ls-remote are verified.

Only the structured history, generated CHANGELOG and historical-compatibility test change. Runtime source and validation producers are byte-identical to main; no native comparisons or timing samples were rerun. Current-head supported hosted checks and package qualification remain required before ordinary merge.

AI assistance

Codex found the drift, checked actual GitHub/PyPI records and the annotated tag, prepared the structured history, regenerated the output, corrected the historical-retention assertion and ran the failing-base, passing-fix and missing-history checks. Codex drafted this description; no independent human review is asserted.

This is release-history maintenance. It creates no release, tag, PyPI publication or deployment, and 0.1.13 remains explicitly Unreleased.