Link published distribution release checkpoints

[arjitj2]

Refs #89.

What changed

Link the nine published checkpoints from 1.6.0 through 1.8.5 in CHANGELOG.md. Correct the 1.8.4 PR label and clarify that retained terminal error/result text can still quote task content in 1.8.5.

Release notes preserve each version's original merge commit, incorporated Cursor baseline, validation record and known limits. Later checkpoints remain draft pending the documented Claude checks or an explicit release exception.

Verification

• Published tags match their original merge SHAs. Each plugin tree matches the corresponding tested PR candidate; all preexisting tags are unchanged.
• GitHub release bodies, draft status, and latest designation were read back and checked against the prepared inventory.
• Documentation checks and 16 documentation tests, 27 maintenance tests, ledger validation, strict typecheck, static invariants, and Claude plugin validation pass.
• All 742 Bun tests pass with zero failures. The local test/typecheck processes used the bundled Node runtime because the ambient Homebrew Node has a missing library.
• Only CHANGELOG.md changes. The packaged plugin tree remains byte-identical to main at 3cd847b. There is no affected installation or runtime behavior in this maintenance change.

Documentation impact

CHANGELOG.md records the published checkpoint links. Existing GitHub release notes now carry their validation evidence and known limits.

GitHub Actions CI passed on c1ba734. Copilot review was requested and returned a quota-limit notice without code findings.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[arjitj2]

Independent maintenance verification: PASS for head c1ba734 against base 3cd847b.

Only CHANGELOG.md changes. The packaged plugin tree remains 8bf32690c3e41d0b047d80a198a0d73209d2b140. The nine tag links identify published checkpoints at their original commits. The corrected PR label and terminal-text privacy caveat are accurate. Documentation checks, 16 documentation tests, ledger validation, and whitespace checks passed in a separate detached checkout. No blocking findings.

The parent separately read back the live GitHub tags and releases, checked all existing tags unchanged and all new tag SHAs against the inventory, and confirmed latest v1.8.5 with three later releases still draft. All742 local tests and GitHub CI passed. Copilot returned a quota notice, not an approval; no review threads remain.