docs: prep CHANGELOG for 3.3.1 release

[justin808]

Summary

• Adds the Propshaft asset version cache busting fix ([codex] Fix Propshaft asset version cache busting #1403) to the changelog.
• Moves the Unreleased entries (Fix default layout handling for render component #1418, fix: remove dependencies that are not used directly #1420, [codex] Fix Propshaft asset version cache busting #1403) under a dated [3.3.1] - 2026-05-15 section.
• Adds the [3.3.1] compare link and updates the [Unreleased] link base.
• Adds a trailing period to the fix: remove dependencies that are not used directly #1420 bullet for consistency.

3.3.1 is a patch release — only bug fixes, no new features or breaking changes. The next step is rake create_release[3.3.1,false] which bumps lib/react/rails/version.rb and package.json and publishes.

Test plan

• git diff shows only CHANGELOG.md changes
• CI green
• Run rake create_release[3.3.1,false] after merge

[claude]

Code Review

Overview: This PR backfills the CHANGELOG.md Unreleased section with the Propshaft cache-busting fix from #1403, which was merged after the v3.3.0 tag but was not yet documented. It also adds a trailing period to the #1420 bullet for consistency.

---

What's Good

• Correct placement — [codex] Fix Propshaft asset version cache busting #1403 merged post-v3.3.0, so Unreleased is the right section.
• The description is clear and user-facing ("server-rendered bundles invalidate correctly when assets change").
• Consistency fix for the missing period on the fix: remove dependencies that are not used directly #1420 entry is a nice touch.

---

Suggestions

1. Missing author attribution

Every other entry in the Unreleased section credits the author with a by [name](url) link:

- Preserve default controller layouts … by [justin808](https://github.com/justin808).
- Remove unneeded runtime dependencies … by [G-Rath](https://github.com/g-rath).

The new line drops the author entirely:

- Fix Propshaft asset version cache busting … [PR 1403](…).

Suggest adding: by [justin808](https://github.com/justin808) before the period for consistency.

2. Missing issue cross-reference

PR #1403's description says it fixes #1358. The PR 1418 entry models the pattern:

Fixes [#1356](https://github.com/reactjs/react-rails/issues/1356).

Adding Fixes [#1358](https://github.com/reactjs/react-rails/issues/1358) gives readers a direct link to the original bug report.

Suggested final line:

- Fix Propshaft asset version cache busting so server-rendered bundles invalidate correctly when assets change. [PR 1403](https://github.com/reactjs/react-rails/pull/1403) by [justin808](https://github.com/justin808). Fixes [#1358](https://github.com/reactjs/react-rails/issues/1358).

---

Other Observations

• No code logic is changed — this is documentation-only, so there are no correctness, performance, or security concerns.
• CI is noted as pending in the PR checklist; assuming it's a CHANGELOG-only change, CI should pass trivially.

---

Summary: Minor but worthwhile — please add the author attribution and issue link to match the established CHANGELOG conventions before merging.

[claude]

Code Review: PR #1426 — CHANGELOG prep for 3.3.1

Overview

This is a documentation-only PR that prepares the CHANGELOG for the upcoming 3.3.1 patch release. The changes are minimal and low-risk: moving three unreleased bug-fix entries into a dated [3.3.1] section and updating the comparison links accordingly.

---

What looks good

• Correct Keep a Changelog structure: The ## [3.3.1] - 2026-05-15 header is inserted in the right place, the [Unreleased] section is left empty (with only the template guidance text), and the versioned compare links at the bottom are updated consistently.
• Trailing period consistency: Adding the missing period to the fix: remove dependencies that are not used directly #1420 bullet is a nice touch.
• Compare links are correct: [Unreleased] now points from v3.3.1...main and the new [3.3.1] link covers v3.3.0...v3.3.1. Both will resolve correctly once the tag is pushed.

---

Suggestions / Issues

1. Missing contributor attribution on the #1403 entry (minor, consistency)

The two existing bullets credit their authors:

- … [PR 1418](…) by [justin808](…).
- … [PR 1420](…) by [G-Rath](…).

But the new entry does not:

- Fix Propshaft asset version cache busting … [PR 1403](…).

For consistency with every other entry in the file, please add the contributor, e.g.:

- Fix Propshaft asset version cache busting so server-rendered bundles invalidate correctly when assets change. [PR 1403](https://github.com/reactjs/react-rails/pull/1403) by [<author>](https://github.com/<author>).

2. Date is 2026-05-15, but today is 2026-05-16 (minor)

Likely reflects the intended release date or a timezone difference — not a blocker, but worth confirming this is intentional.

---

Security / Performance / Test coverage

No concerns — this PR touches only CHANGELOG.md. There is no executable code, no new dependencies, and no test changes needed.

---

Summary

This is a clean, focused release-prep PR. The one actionable item before merge is adding the missing contributor credit to the #1403 entry so the changelog stays consistent. Everything else looks good.