feat: componentize GStack 2 runtime and release integrity

.github/workflows/windows-free-tests.yml

@@ -1,5 +1,8 @@
 name: Windows Free Tests
 
+permissions:
+  contents: read
+
 # Curated subset of the free test suite that runs on a paid faster Windows runner.
 #
 # Codex's v1.18.0.0 review flagged that the existing evals.yml workflow uses
@@ -39,11 +42,11 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
-      - uses: oven-sh/setup-bun@v1
+      - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
         with:
-          bun-version: latest
+          bun-version: 1.3.14
 
       - name: Configure git identity (required by tests that init temp repos)
         run: |