Add release verification workflow

[kitsuyui]

Summary

• Add a release workflow that runs release validation on GitHub Release events and manual tag verification.
• Add a release version verification script and package script so release tags are checked against package.json and the action entrypoint.
• Document the release process in the README.

Checks

• git diff --check
• typos README.md package.json scripts/verify-release-version.mjs .github/workflows/release.yml
• go run github.com/rhysd/actionlint/cmd/actionlint@v1.7.12 -color
• bun x biome check --vcs-use-ignore-file=false README.md package.json scripts/verify-release-version.mjs .github/workflows/release.yml
• RELEASE_TAG=v0.9 bun run release:verify
• bun run test
• bun run build
• collateral check: clean

Notes

• The local validation checkout cannot faithfully reproduce the workflow dist diff gate because generated source maps include checkout-relative paths; GitHub Actions remains the source of truth for the standard checkout.
• bun run lint is also affected by the local ignored-checkout path, so Biome was run directly against the changed files with VCS ignore-file integration disabled.

[github-actions]

🎉 Happy commit!

• dogfooding: PR Add release verification workflow #847 always celebrates.
• dogfooding: c16a7eb13d65c612fee66d13d2f4800e9c053dcd always celebrates.

[github-actions]

Code Metrics Report

	main (8bad195)	#847 (54e8897)	+/-
Coverage	99.2%	99.2%	0.0%
Code to Test Ratio	1:1.3	1:1.3	0.0
Test Execution Time	2s	1s	-1s

Details

  |                     | main (8bad195) | #847 (54e8897) | +/-  |
  |---------------------|----------------|----------------|------|
  | Coverage            |          99.2% |          99.2% | 0.0% |
  |   Files             |              5 |              5 |    0 |
  |   Lines             |            134 |            134 |    0 |
  |   Covered           |            133 |            133 |    0 |
  | Code to Test Ratio  |          1:1.3 |          1:1.3 |  0.0 |
  |   Code              |            723 |            723 |    0 |
  |   Test              |            955 |            955 |    0 |
+ | Test Execution Time |             2s |             1s |  -1s |

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Reported by octocov