Address PR review feedback for pr-metadata-check workflow

- Fix case sensitivity: 'nvidia' → 'NVIDIA' (job never ran as-is)
- Re-add milestoned/demilestoned activity types (valid for pull_request_target)
- Update copyright year to include 2026
- Add PR metadata guidance to AGENTS.md for label/milestone enforcement

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

Author: rparolin

.github/workflows/pr-metadata-check.yml

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 
@@ -12,12 +12,14 @@ on:
       - synchronize
       - labeled
       - unlabeled
+      - milestoned
+      - demilestoned
 
 jobs:
   check-metadata:
     name: PR has labels and milestone
-    if: github.repository_owner == 'nvidia'
     if: github.repository_owner == 'NVIDIA'
+    runs-on: ubuntu-latest
     steps:
       - name: Check for labels and milestone
         env:

AGENTS.md

@@ -12,6 +12,22 @@ guide for package-specific conventions and workflows.
 - `cuda_core/`: High-level Pythonic CUDA APIs built on top of bindings.
 - `cuda_python/`: Metapackage and docs aggregation.
 
+# Pull requests
+
+When creating pull requests with `gh pr create`, always assign at least one
+label and a milestone. CI enforces this via the `pr-metadata-check` workflow
+and will block PRs that are missing labels or a milestone. Use `--label` and
+`--milestone` flags, for example:
+
+```
+gh pr create --title "..." --body "..." --label "bug" --milestone "v1.0"
+```
+
+If you are unsure which label or milestone to use, check the existing labels
+and milestones on the repository with `gh label list` and `gh api
+repos/{owner}/{repo}/milestones --jq '.[].title'`, and pick the best match.
+
+
 # General
 
 - When searching for text or files, prefer using `rg` or `rg --files`