## Summary
Perf report workflow fails on fork PRs because `GITHUB_TOKEN` is
read-only for forks, causing "Resource not accessible by integration" on
the PR comment step.
## Changes
- **What**: Split `ci-perf-report.yaml` into a data-collection workflow
+ a `workflow_run`-triggered reporter (`pr-perf-report.yaml`), matching
the existing `ci-size-data`/`pr-size-report` pattern. Added fork PR
permissions guidance to `.github/AGENTS.md`.
- **ci-perf-report.yaml**: Removed the `report` job and `pull-requests:
write` permission. Added PR metadata (number + base branch) artifact
upload.
- **pr-perf-report.yaml** (new): Triggered by `workflow_run` on the perf
workflow. Downloads metrics + metadata artifacts, generates report,
posts PR comment with write permissions from the default-branch context.
## Review Focus
- The two-workflow split follows the same pattern as `ci-size-data.yaml`
→ `pr-size-report.yaml`, which already works for fork PRs.
- The `workflow_run` trigger runs in the base repo context per [GitHub
Security Lab
guidance](https://securitylab.github.com/resources/github-actions-preventing-pwn-requests/),
so it safely has write permissions even for fork PRs.
- AGENTS.md guidance documents this pattern to prevent recurrence.
Fixes the failure seen in
https://github.com/Comfy-Org/ComfyUI_frontend/actions/runs/22684230751/job/65763595989?pr=9380
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9382-fix-split-perf-report-workflow-for-fork-PR-support-3196d73d365081b29b35ed354e7789e2)
by [Unito](https://www.unito.io)