chore(ci): establish PR governance for agent collaboration (#177)

* chore(ci): establish PR governance for agent collaboration

* docs: add AGENTS playbook and strengthen agent collaboration workflow

---------

Co-authored-by: chumyin <183474434+chumyin@users.noreply.github.com>

.github/workflows/auto-response.yml

@@ -0,0 +1,40 @@
+name: Auto Response
+
+on:
+  issues:
+    types: [opened]
+  pull_request_target:
+    types: [opened]
+
+permissions: {}
+
+jobs:
+  first-interaction:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Greet first-time contributors
+        uses: actions/first-interaction@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          issue-message: |
+            Thanks for opening this issue.
+
+            Before maintainers triage it, please confirm:
+            - Repro steps are complete and run on latest `main`
+            - Environment details are included (OS, Rust version, ZeroClaw version)
+            - Sensitive values are redacted
+
+            This helps us keep issue throughput high and response latency low.
+          pr-message: |
+            Thanks for contributing to ZeroClaw.
+
+            For faster review, please ensure:
+            - PR template sections are fully completed
+            - `cargo fmt --all -- --check`, `cargo clippy --all-targets -- -D warnings`, and `cargo test` are included
+            - If automation/agents were used heavily, add brief workflow notes
+            - Scope is focused (prefer one concern per PR)
+
+            See `CONTRIBUTING.md` and `docs/pr-workflow.md` for full collaboration rules.