feat: add large summary handling with artifact upload

When the dependency review summary exceeds GitHub's size limit (1024k), upload it as an artifact and provide a link in the comment. This ensures users can still access the full review details even when the summary is too large to display directly.

package.json

@@ -25,6 +25,7 @@
   "author": "GitHub",
   "license": "MIT",
   "dependencies": {
+    "@actions/artifact": "^2.3.2",
     "@actions/core": "^1.11.1",
     "@actions/github": "^6.0.1",
     "@octokit/plugin-retry": "^6.1.0",

src/main.ts

@@ -24,6 +24,8 @@ import {getRefs} from './git-refs'
 import {groupDependenciesByManifest} from './utils'
 import {commentPr, MAX_COMMENT_LENGTH} from './comment-pr'
 import {getDeniedChanges} from './deny'
+import * as artifact from '@actions/artifact'
+import * as fs from 'fs'
 
 async function delay(ms: number): Promise<void> {
   return new Promise(resolve => setTimeout(resolve, ms))
@@ -61,6 +63,41 @@ async function getComparison(
   return comparison
 }
 
+export async function handleLargeSummary(
+  summaryContent: string
+): Promise<string> {
+  const MAX_SUMMARY_SIZE = 1024 * 1024 // 1024k in bytes
+  if (Buffer.byteLength(summaryContent, 'utf8') <= MAX_SUMMARY_SIZE) {
+    return summaryContent
+  }
+
+  const artifactClient = new artifact.DefaultArtifactClient()
+  const artifactName = 'dependency-review-summary'
+  const files = ['summary.md']
+
+  try {
+    // Write the summary to a file
+    await fs.promises.writeFile('summary.md', summaryContent)
+
+    // Upload the artifact
+    await artifactClient.uploadArtifact(artifactName, files, '.', {
+      retentionDays: 1
+    })
+
+    // Return a minimal summary with a link to the artifact
+    return `# Dependency Review Summary
+
+The full dependency review summary is too large to display here. Please download the artifact named "${artifactName}" to view the complete report.
+
+[View full job summary](${process.env.GITHUB_SERVER_URL}/${process.env.GITHUB_REPOSITORY}/actions/runs/${process.env.GITHUB_RUN_ID})`
+  } catch (error) {
+    core.warning(
+      `Failed to handle large summary: ${error instanceof Error ? error.message : 'Unknown error'}`
+    )
+    return summaryContent
+  }
+}
+
 async function run(): Promise<void> {
   try {
     const config = await readConfig()
@@ -179,6 +216,9 @@ async function run(): Promise<void> {
     let rendered = core.summary.stringify()
     core.setOutput('comment-content', rendered)
 
+    // Handle large summaries by uploading as artifact
+    rendered = await handleLargeSummary(rendered)
+
     // if the summary is oversized, replace with minimal version
     if (rendered.length >= MAX_COMMENT_LENGTH) {
       core.debug(