chore(ci): remove vp env off E2E steps, covered by snap test

The snap test command-env-off-on now covers system-first mode
switching with runtime assertions, making the CI E2E steps redundant.

Author: fengmk2

.github/workflows/ci.yml

@@ -235,11 +235,6 @@ jobs:
         if: ${{ matrix.target == 'x86_64-unknown-linux-gnu' }}
         run: pnpm tsgo
 
-      - name: Save system Node.js info
-        run: |
-          echo "SYSTEM_NODE_PATH=$(which node)" >> "$GITHUB_ENV"
-          echo "SYSTEM_NODE_VERSION=$(node --version)" >> "$GITHUB_ENV"
-
       - name: Install Global CLI vp
         run: |
           pnpm bootstrap-cli:ci
@@ -263,28 +258,6 @@ jobs:
         env:
           RUST_MIN_STACK: 8388608
 
-      - name: Test vp env off (system-first mode)
-        run: |
-          echo "System Node.js: $SYSTEM_NODE_PATH ($SYSTEM_NODE_VERSION)"
-
-          vp env off
-          vp env doctor
-
-          # Verify vp --version still works using system Node.js
-          vp --version
-
-          # In system-first mode, the node shim should resolve to system node
-          SHIM_NODE_VERSION=$(node --version)
-          echo "Shim Node.js version: $SHIM_NODE_VERSION"
-          if [ "$SHIM_NODE_VERSION" != "$SYSTEM_NODE_VERSION" ]; then
-            echo "Error: expected shim to use system Node.js $SYSTEM_NODE_VERSION, got $SHIM_NODE_VERSION"
-            exit 1
-          fi
-
-          vp env on
-          vp env doctor
-          echo "vp env off/on test passed"
-
       - name: Test global package install (powershell)
         if: ${{ matrix.os == 'windows-latest' }}
         shell: pwsh
@@ -325,27 +298,6 @@ jobs:
           vp env use --unset
           node --version
 
-      - name: Test vp env off (powershell)
-        if: ${{ matrix.os == 'windows-latest' }}
-        shell: pwsh
-        run: |
-          Write-Host "System Node.js: $env:SYSTEM_NODE_PATH ($env:SYSTEM_NODE_VERSION)"
-
-          vp env off
-          vp env doctor
-          vp --version
-
-          $ShimNodeVersion = node --version
-          Write-Host "Shim Node.js version: $ShimNodeVersion"
-          if ($ShimNodeVersion -ne $env:SYSTEM_NODE_VERSION) {
-            Write-Error "Expected shim to use system Node.js $env:SYSTEM_NODE_VERSION, got $ShimNodeVersion"
-            exit 1
-          }
-
-          vp env on
-          vp env doctor
-          Write-Host "vp env off/on test passed"
-
       - name: Test global package install (cmd)
         if: ${{ matrix.os == 'windows-latest' }}
         shell: cmd