refactor(ci): plumb regenerated PR lockfile via artifact

The policy job already regenerates pnpm-lock.yaml in memory when a PR
changes any manifest (package.json, pnpm-workspace.yaml, .npmrc,
pnpmfile.*) but throws it away. Manifest-only PRs from non-dependabot,
non-chore/refresh-lockfile branches can't commit the lockfile (policy
blocks it) and can't satisfy --frozen-lockfile downstream, so every
test/build job fails with ERR_PNPM_OUTDATED_LOCKFILE until the
post-merge refresh-lockfile workflow runs on master.

This commit closes that gap by uploading the regenerated lockfile as
a workflow artifact (pr-lockfile) from policy and restoring it via
actions/download-artifact in each downstream job before pnpm install
--frozen-lockfile runs. The download step is best-effort
(continue-on-error: true) so PRs that did not change manifests are
unaffected — the artifact simply does not exist and downstream jobs
proceed with the committed lockfile as before. canary_dry_run's
pre-existing 'git checkout -- pnpm-lock.yaml' is guarded so it no
longer clobbers an artifact-restored lockfile.

.github/workflows/pr.yml

@@ -13,6 +13,8 @@ jobs:
   policy:
     runs-on: ubuntu-latest
     timeout-minutes: 5
+    outputs:
+      lockfile_regenerated: ${{ steps.regen_lockfile.outputs.regenerated }}
 
     steps:
       - name: Checkout repository
@@ -63,13 +65,30 @@ jobs:
             node ./scripts/check-release-package-bootstrap.mjs "${changed_paths[@]}"
 
       - name: Validate dependency resolution when manifests change
+        id: regen_lockfile
         run: |
           changed="$(git diff --name-only "${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }}")"
           manifest_pattern='(^|/)package\.json$|^pnpm-workspace\.yaml$|^\.npmrc$|^pnpmfile\.(cjs|js|mjs)$'
           if printf '%s\n' "$changed" | grep -Eq "$manifest_pattern"; then
             pnpm install --lockfile-only --ignore-scripts --no-frozen-lockfile
+            echo "regenerated=1" >> "$GITHUB_OUTPUT"
+          else
+            echo "regenerated=0" >> "$GITHUB_OUTPUT"
           fi
 
+      # Manifest-only PRs (where pnpm-lock.yaml stays at base because the policy
+      # job above blocks committing it) need the regenerated lockfile for the
+      # downstream `pnpm install --frozen-lockfile` steps. Upload it here so
+      # every job consumes the same hash without recomputing.
+      - name: Upload regenerated lockfile for downstream jobs
+        if: steps.regen_lockfile.outputs.regenerated == '1'
+        uses: actions/upload-artifact@v4
+        with:
+          name: pr-lockfile
+          path: pnpm-lock.yaml
+          retention-days: 1
+          if-no-files-found: error
+
   typecheck_release_registry:
     name: Typecheck + Release Registry
     needs: [policy]
@@ -85,6 +104,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
@@ -125,6 +151,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
@@ -171,6 +204,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
@@ -214,6 +254,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
@@ -241,6 +288,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with:
@@ -251,11 +305,20 @@ jobs:
         run: pnpm install --frozen-lockfile
 
       # `release.sh` always executes its Step 2/7 workspace build, even when
-      # `--skip-verify` bypasses the initial verification gate.
+      # `--skip-verify` bypasses the initial verification gate. release.sh
+      # also requires a clean working tree, so any in-place lockfile churn
+      # from `pnpm install --frozen-lockfile` must be reverted first — unless
+      # the policy job uploaded a regenerated lockfile (manifest-only PRs),
+      # in which case we keep the artifact-restored copy so the workspace
+      # build sees a lockfile that matches the manifest.
       - name: Release canary dry run via release.sh internal build
+        env:
+          USED_ARTIFACT_LOCKFILE: ${{ needs.policy.outputs.lockfile_regenerated || '0' }}
         run: |
           git checkout -B master HEAD
-          git checkout -- pnpm-lock.yaml
+          if [ "$USED_ARTIFACT_LOCKFILE" != "1" ]; then
+            git checkout -- pnpm-lock.yaml
+          fi
           ./scripts/release.sh canary --skip-verify --dry-run
 
   e2e:
@@ -272,6 +335,13 @@ jobs:
         with:
           version: 9.15.4
 
+      - name: Restore regenerated PR lockfile (if policy uploaded one)
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: pr-lockfile
+          path: .
+
       - name: Setup Node.js
         uses: actions/setup-node@v6
         with: