ci: cargo audit + SHA-pin all GHA action refs + enforcement lint (#1539)

.github/workflows/opencode-code-review.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout PR head
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
@@ -215,7 +215,7 @@ jobs:
 
       - name: Upload OpenCode review artifacts
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: opencode-review-same-repo-${{ github.event.pull_request.number }}
           path: .opencode-review/
@@ -234,7 +234,7 @@ jobs:
     permissions:
       pull-requests: write
     steps:
-      - uses: actions/github-script@v7
+      - uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
         with:
           script: |
             try {
@@ -270,7 +270,7 @@ jobs:
 
     steps:
       - name: Checkout PR head
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
         with:
           # pull_request_target checks out the base branch by default; explicitly
           # check out the contributor's head via the base repository PR ref.
@@ -454,7 +454,7 @@ jobs:
 
       - name: Upload OpenCode review artifacts
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: opencode-review-fork-${{ github.event.pull_request.number }}
           path: .opencode-review/