Add Copilot code review quality guidance (#3665)

* Add Copilot code review quality guidance

Add a repository-specific Copilot Code Review skill for repo-fit, provenance, differentiation, validation, and marketing-signal review. Wire it into the repo review instructions and CODEOWNERS, add an advisory PR quality-signal workflow, and tighten the Learning Hub updater instructions to reuse existing bot PRs instead of creating duplicate stale update PRs.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Fix PR review workflow feedback

Add constrained safe outputs for reusing and closing Learning Hub bot pull requests, and declare the quality-signal workflow name in source frontmatter.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Upgrade agentic workflows

Rebase the PR onto main and upgrade gh-aw to v0.88.8. Refresh setup actions, generated workflow locks, container pins, and updater permissions.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

.github/workflows/learning-hub-updater.md

@@ -7,11 +7,15 @@ on:
 permissions:
   contents: read
   copilot-requests: write
+  pull-requests: read
 tools:
   edit:
   web-fetch:
   github:
-    toolsets: [repos]
+    toolsets: [repos, pull_requests]
+checkout:
+  fetch: ["*"]
+  fetch-depth: 0
 safe-outputs:
   allowed-domains:
     - github.com
@@ -22,6 +26,19 @@ safe-outputs:
     labels: [automated-update, copilot-updates]
     title-prefix: "[bot] "
     base-branch: main
+    allowed-files:
+      - "website/learning-hub/**/*.md"
+  push-to-pull-request-branch:
+    target: "*"
+    required-title-prefix: "[bot] "
+    required-labels: [automated-update, copilot-updates]
+    allowed-files:
+      - "website/learning-hub/**/*.md"
+  close-pull-request:
+    target: "*"
+    required-labels: [automated-update, copilot-updates]
+    required-title-prefix: "[bot] "
+    max: 5
 ---
 
 # Check for Awesome GitHub Copilot Updates
@@ -92,9 +109,31 @@ To create a new page:
 
 If the new information can be added to existing pages, edit those pages to include refinements, new sections, or updated information as needed, following the content model above. Make sure to update any relevant links in the "Further Reading" sections.
 
-## Step 4 — Open a pull request
+## Step 4 — Reuse or update the existing bot pull request
 
-Create a pull request with your changes, using the `main` branch as the base branch. The PR title should summarize what was updated (e.g., "Add/plan command and model marketplace documentation"). The PR body should list:
+Before opening a new pull request, use GitHub pull request tooling to find open
+PRs with the `automated-update` and `copilot-updates` labels and a `[bot] `
+title prefix. Identify whether any matching PR is already updating the same
+Learning Hub area.
+
+If a matching PR already exists:
+
+1. Use the `push_to_pull_request_branch` safe-output tool to push the changes
+   onto that PR's branch instead of creating a new PR. This tool can only target
+   PRs that carry both labels and the `[bot] ` title prefix.
+2. Keep the branch and title stable so the update remains a single, current
+   review thread.
+3. If an older matching PR is stale or clearly superseded by the newer content,
+   use the `close_pull_request` safe-output tool to close it with a short
+   explanation such as "Superseded by newer automated update".
+4. Prefer a single active PR that reflects the latest information.
+
+Only use the `create_pull_request` safe-output tool to open a fresh PR when no
+relevant open bot PR exists for the same content area.
+
+When creating a new PR, use the `main` branch as the base branch. The PR title
+should summarize what was updated (for example, "Add/plan command and model
+marketplace documentation"). The PR body should list:
 
 1. What new features or changes were found
 2. What sections of the guide were updated
@@ -102,3 +141,16 @@ Create a pull request with your changes, using the `main` branch as the base bra
 4. **Content cleanup** — what older inline version notes were consolidated, rewritten as current behavior, or moved into a Compatibility and Migration Notes section, or a brief note that none needed changes this run
 
 The PR should target the `main` branch and include the labels `automated-update` and `copilot-updates`.
+
+## Step 5 — Avoid duplicate bot churn
+
+Do not create a new PR when the same content is already being tracked in a
+current open bot PR — push to it instead (Step 4).
+
+If the repo already has one or more older bot PRs for near-identical Learning Hub changes, prefer to:
+
+- push the update to the newest relevant PR via `push_to_pull_request_branch`
+- close stale duplicates via `close_pull_request` with a short explanation such as "Superseded by newer automated update"
+- avoid leaving the maintainers to triage multiple almost-identical docs PRs
+
+This keeps the automation loop tight and reduces review noise.