Expand release changelog and scope game-test readiness

[aaf2tbz]

Summary

Expand the release changelog through v0.74.0 and make live-game verification conditional on changes that can affect game launches or compatibility.

Changes

• Document every tagged release from v0.54.5 through v0.74.0, including the major visual/product update denoted by the intentional jump to v0.70.0.
• Update PR readiness CI to inspect changed files and require a real-game launch test only for game launch, graphics, compatibility, or game-library changes.
• Update the PR template to explain when a real-game test is applicable.

PR Readiness

• Real-game launch test completed for game/runtime/graphics/compatibility changes (game + method below; otherwise mark N/A) — N/A; this PR changes the changelog and readiness checklist only, so CI skips the live-game requirement.
• No hardcoded paths, secrets, or absolute /Users/... paths introduced
• Config/rules TOML validated if configs/mtsp-rules.toml or DLL maps changed — no rules/DLL map files changed
• Version metadata (CMakeLists.txt, app/src-c/Makefile, package.json, package-lock.json) in sync if version bumped — no version bump
• Bottle/runtime migration and launch behavior preserved (rollback plan noted if changed) — no runtime behavior changed
• Docs / compatibility matrix updated for user-facing changes
• Regression test added for each bug fix — no bug fix in this documentation/CI PR

Local validation

• actionlint .github/workflows/pr-readiness-check.yml
• Conditional-path checks verify docs-only changes do not require a game launch and launch/rules/native compatibility paths do
• git diff --check
• python3 tools/ci/check-doc-freshness.py recognizes the current changelog section (it reports pre-existing missing Updated: headers for README and two guides)

Test notes

No game or application launch was needed. Changed-file classification was checked against representative game-launch/runtime/graphics/compatibility paths and this PR’s documentation/CI paths.

Risk

No application runtime behavior changes. The readiness gate now scopes live-game smoke testing to changes likely to affect actual game launch or compatibility.