ci: adopt the setup-pnpm composite action at all 16 remaining Corepack sites

`corepack enable` only writes shims; the pnpm tarball is fetched from
registry.npmjs.org on the first pnpm invocation in the job. Every such site
is an independent chance for a network flake to fail a job for a reason that
has nothing to do with the code under test.

The setup-pnpm composite action removes that call by restoring the Corepack
store from the actions cache. It was introduced for ci.yml, which now has
zero Corepack sites. This applies it to the ten workflows that still had one.

Counts across .github/workflows/ (before -> after):

  corepack enable occurrences   16 -> 0   (10 files -> 0)
  uses: ./.github/actions/setup-pnpm      7 -> 23  (+16, the matching amount)
  name: Verify pnpm version      8 -> 0   (folded into the composite)
  uses: actions/setup-node@      32 -> 32 (unchanged, deliberately)

Every caller keeps its own actions/setup-node step with its literal
node-version pin. scripts/check-node-version.mjs scans .github/workflows/*.yml
only and reports how many setup-node steps it audited; moving those steps into
the composite would drop them from its census while it still printed OK. It
still reports 32 setup-node steps across 26 workflows.

The two sites whose Corepack step was conditional keep their condition
verbatim on the composite step, and stay in position:

  pr-automation.yml  changeset-check   (skip label / diff-base guard)
  release.yml        release-integrity (deferred to the repair path only)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015ahemw8RcTgqtxrj15PEZx

Author: claude

.github/workflows/coverage-nightly.yml

@@ -28,8 +28,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/cut-rc.yml

@@ -339,11 +339,8 @@ jobs:
           # hotcrm@v1.2.0, whose manifest pins engines.node >=22.
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/lint.yml

@@ -56,8 +56,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash
@@ -2496,11 +2496,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash
@@ -3072,11 +3069,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash
@@ -3249,11 +3243,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash
@@ -3443,11 +3434,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/pr-automation.yml

@@ -423,11 +423,11 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
+      - name: Setup pnpm
         if: >-
           steps.labels.outputs.skip != 'true'
           && steps.diffbase.outputs.base_error == ''
-        run: corepack enable
+        uses: ./.github/actions/setup-pnpm
 
       - name: Install dependencies
         if: >-

.github/workflows/publish-smoke.yml

@@ -191,8 +191,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/release.yml

@@ -274,11 +274,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash
@@ -507,9 +504,9 @@ jobs:
 
       # Everything below is skipped on the overwhelmingly common path (nothing to
       # repair), which is why the install is here rather than at the top of the job.
-      - name: Enable Corepack
+      - name: Setup pnpm
         if: steps.audit.outputs.releases-missing == 'true'
-        run: corepack enable
+        uses: ./.github/actions/setup-pnpm
 
       - name: Install dependencies
         if: steps.audit.outputs.releases-missing == 'true'
@@ -670,11 +667,8 @@ jobs:
             echo "  see the run's deployment history for the reviewer and timestamp"
           } >> "$GITHUB_STEP_SUMMARY"
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/rerun-safety-nightly.yml

@@ -54,8 +54,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/scaffold-e2e.yml

@@ -52,8 +52,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash

.github/workflows/spec-liveness-check.yml

@@ -45,8 +45,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Install dependencies
         run: pnpm install --frozen-lockfile

.github/workflows/validate-deps.yml

@@ -39,11 +39,8 @@ jobs:
         with:
           node-version: '22'
 
-      - name: Enable Corepack
-        run: corepack enable
-
-      - name: Verify pnpm version
-        run: pnpm --version
+      - name: Setup pnpm
+        uses: ./.github/actions/setup-pnpm
 
       - name: Get pnpm store directory
         shell: bash