fix: show published npm version in PR artifact comment

[ranxianglei]

Problem

PR #298's bot comment showed the npm tag (pr-298) but not the actual published version number. Users couldn't verify which version corresponds to the current PR state on npm.

Fix

Pass the published version from the npm publish step to the PR comment step via GITHUB_OUTPUT. The comment now shows:

**Published:** `opencode-acp@1.14.16-pr.298.5`
Current version: `1.14.16-pr.298.5` (npm tag `pr-298`)

Files Changed

• .github/workflows/pr-artifact.yml — added id: npm-publish + outputs, comment reads version

[github-actions]

📦 Built Plugin Artifact

Branch: 2026-08-13_pr-artifact-version-display (9ff312b)

Option A — Install from npm PR tag (recommended)

opencode plugin opencode-acp@pr-299 --global

Each push to this PR publishes a new version under the pr-299 npm tag.

Option B — Install from GitHub

opencode plugin "github:ranxianglei/opencode-acp#2026-08-13_pr-artifact-version-display" --global

Option C — Download artifact

1. Download the artifact from the Actions run
2. Extract the tarball and install:

tar xzf opencode-acp-pr299.tgz
cp -r package/dist ~/.cache/opencode/packages/opencode-acp@latest/node_modules/opencode-acp/dist

3. Restart opencode to pick up changes.

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This comment is automatically updated on each push.