feat: render structured output for step log, job summary, and PR comments

Collect results via commit-check --format json and render all three
output surfaces from the structured data instead of scraping plain text:

- step log: grouped sections with ::error annotations per rule ID
- job summary: policy report table with rule links and collapsible details
- PR comment: compact table with rule links and collapsible details
- new result output exposing structured JSON for downstream jobs

Author: shenxianpeng

README.md

@@ -201,6 +201,28 @@ for all available options.
 > [Optional Inputs](#optional-inputs), so env vars and config files are the
 > recommended way to customize.
 
+## Outputs
+
+### `result`
+
+Structured check results as JSON, available to downstream steps via
+[`fromJSON`](https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs#fromjson):
+
+```yaml
+- uses: commit-check/commit-check-action@v2
+  id: commit-check
+
+- name: Inspect results
+  run: |
+    echo "Status: ${{ fromJSON(steps.commit-check.outputs.result).status }}"
+    echo "Scopes: ${{ toJSON(fromJSON(steps.commit-check.outputs.result).scopes) }}"
+```
+
+Each scope carries the check outcomes (`rule_id`, `check`, `status`, `value`,
+`error`, `suggest`, `docs_url`) exactly as produced by
+`commit-check --format json`, so downstream jobs can build their own reports
+or gate on individual rules.
+
 ## GitHub Action Job Summary
 
 By default, commit-check-action results are shown on the job summary page of the workflow.

action.yml

@@ -37,6 +37,10 @@ inputs:
     description: check pull request title following conventional commits
     required: false
     default: false
+outputs:
+  result:
+    description: Structured check results as JSON (status + per-scope checks). Consume with fromJSON(steps.<id>.outputs.result).
+
 runs:
   using: "composite"
   steps: