fix: record release versions in pull requests

[dkstm95]

Goal

• User result: release necessity and exact version changes are enforced by the repository instead of being left to AI instructions.
• Why it is needed: the previous workflow chose a version after merge, failed to push its release commit to protected main, and left package changes after v2.0.0 unreleased.
• Not included: automatically deciding whether a public change is patch, minor, or major.

Change

• Before: commit subjects selected a release type after merge, and the release workflow tried to create and push a version commit.
• After: Verify compares normalized package snapshots at the latest stable tag, PR base, and PR result. Package changes or inherited release debt require exactly one version step; unchanged packages reject an unnecessary step.
• Important decision or tradeoff: AI or review chooses patch, minor, or major; code calculates the exact version, updates the four version files, and blocks an inconsistent PR.

Safety

• Main risk or unknown: parallel PRs may initially select the same next version.
• Ownership or cleanup rule: protected main already requires Verify and an up-to-date branch, so the later PR must recalculate after the first versioned PR merges.
• Release workflow: it only verifies, tags, and publishes the recorded merge commit; it never commits or pushes to main.

Validation

• Commands that ran: npm run release:prepare -- patch; npm run release:check -- origin/main; npm run check; focused release tests; both workflow YAML parses; git diff --check.
• Deterministic result: patch 2.0.0 -> 2.0.1, including inherited package debt.
• Checks not run: browser tests locally, because no Diff layout or interaction changed.
• npm run check

Release

• Decision: patch
• Version: 2.0.1
• Reason: this releases the compatible package changes accumulated after v2.0.0 and fixes the release path that failed to publish them.