feat(ci): add keep_alive option to preserve Brev instance for debugging

Default to keep_alive=true so the instance stays up after tests.
PR comment includes SSH instructions and instance name when alive.
Vitest afterAll skips deletion when KEEP_ALIVE=true.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jyaunches

.github/workflows/e2e-brev.yaml

@@ -23,6 +23,11 @@ on:
           - full
           - credential-sanitization
           - all
+      keep_alive:
+        description: "Keep Brev instance alive after tests (for SSH debugging)"
+        required: false
+        type: boolean
+        default: true
   workflow_call:
     inputs:
       branch:
@@ -36,6 +41,10 @@ on:
         required: false
         type: string
         default: "full"
+      keep_alive:
+        required: false
+        type: boolean
+        default: true
     secrets:
       BREV_API_TOKEN:
         required: true
@@ -101,6 +110,7 @@ jobs:
           GITHUB_TOKEN: ${{ github.token }}
           INSTANCE_NAME: e2e-pr-${{ inputs.pr_number || github.run_id }}
           TEST_SUITE: ${{ inputs.test_suite }}
+          KEEP_ALIVE: ${{ inputs.keep_alive }}
         run: npx vitest run --project e2e-brev --reporter=verbose
 
       - name: Update check run (completed)
@@ -128,7 +138,17 @@ jobs:
             EMOJI="❌"
             STATUS="FAILED"
           fi
+          INSTANCE="e2e-pr-${{ inputs.pr_number || github.run_id }}"
           BODY="${EMOJI} **Brev E2E** (${{ inputs.test_suite }}): **${STATUS}** on branch \`${{ inputs.branch }}\` — [See logs](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})"
+          if [ "${{ inputs.keep_alive }}" = "true" ]; then
+            BODY="${BODY}
+
+          > **Instance \`${INSTANCE}\` is still running.** To SSH in:
+          > \`\`\`
+          > brev refresh && ssh ${INSTANCE}
+          > \`\`\`
+          > When done, delete it: \`brev delete ${INSTANCE}\`"
+          fi
           gh pr comment ${{ inputs.pr_number }} --repo ${{ github.repository }} --body "$BODY"
 
       - name: Upload test logs

test/e2e/brev-e2e.test.js

@@ -144,6 +144,12 @@ describe("Brev E2E", () => {
 
   afterAll(() => {
     if (!instanceCreated) return;
+    if (process.env.KEEP_ALIVE === "true") {
+      console.log(`\n  Instance "${INSTANCE_NAME}" kept alive for debugging.`);
+      console.log(`  To connect: brev refresh && ssh ${INSTANCE_NAME}`);
+      console.log(`  To delete:  brev delete ${INSTANCE_NAME}\n`);
+      return;
+    }
     try {
       brev("delete", INSTANCE_NAME);
     } catch {