(MODULES-11832) Add synced PR template with outcome-based review policy

Add moduleroot/.github/PULL_REQUEST_TEMPLATE.md.erb so every CAT-supported
module gets a synced PR template on `pdk update`. The template enforces the
S2 outcome-based review policy:

- Required checklist: structured-ticket linkage, coverage gate green/baseline
  preserved, platform matrix result link, Co-Authored-By: Claude trailer when
  AI-assisted.
- Outcome-based review lanes (auto-merge / single reviewer / full review),
  consistent with the policy documented in moduleroot/CLAUDE.md.

Managed (not unmanaged) so the policy stays consistent across modules; a
module can opt out via `.sync.yml`. Verified with `pdk convert --noop` on
puppetlabs-lvm: renders to .github/PULL_REQUEST_TEMPLATE.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: imaqsood

moduleroot/.github/PULL_REQUEST_TEMPLATE.md.erb

@@ -0,0 +1,50 @@
+<!--
+  This pull request template is synced from puppetlabs/pdk-templates
+  (moduleroot/.github/PULL_REQUEST_TEMPLATE.md.erb). Do not edit it directly in a
+  module repo -- changes are overwritten on the next `pdk update`. To customise it
+  for a single module, opt out with `.github/PULL_REQUEST_TEMPLATE.md: unmanaged: true`
+  in the module's `.sync.yml` and maintain a hand-written copy.
+-->
+
+## Summary
+
+Describe what this change does and why. Keep the change scoped to the linked ticket;
+flag any unrelated cleanup as a separate ticket/PR.
+
+## Related ticket
+
+<!-- Link the driving ticket using the structured spec template. -->
+- Ticket: MODULES-XXXX
+
+## Required checklist
+
+- [ ] Linked the driving `MODULES-*` ticket above using the structured spec template.
+- [ ] Coverage gate is green (or the baseline is preserved -- coverage was not reduced).
+- [ ] Platform matrix result link included below (CI run or nightly Litmus result).
+- [ ] `Co-Authored-By: Claude` trailer is present on the commits if this PR was AI-assisted.
+
+## Platform matrix result
+
+<!-- Paste the link to the CI / nightly Litmus run that proves the supported OS matrix is green. -->
+
+## Review policy (outcome-based)
+
+PRs are judged on outcomes, not line counts. Pick the lane that matches this change so
+reviewers know what coverage to expect. See `CLAUDE.md` for the full policy.
+
+- **Auto-merge** -- green CI required, no human review needed:
+  dependabot bumps, modulesync / `pdk update` resync, doc-only changes, `REFERENCE.md` regeneration.
+- **Single reviewer** -- green CI plus coverage preserved required:
+  bug fixes, supported-platform additions, simple feature work.
+- **Full review (2 or more reviewers)** -- green CI plus coverage plus senior sign-off:
+  provider / type-API changes, security fixes, breaking changes.
+
+This PR is (check one):
+
+- [ ] Auto-merge
+- [ ] Single reviewer
+- [ ] Full review (2+)
+
+## Additional context
+
+<!-- Root cause, reproduction steps, and the reasoning behind the implementation, if applicable. -->