revert: restore original GitHub Actions versions pre-Dependabot

Reverts Dependabot bump (#180) to original pinned versions:
- actions/checkout@v6 → v4
- actions/setup-python@v6 → v5
- actions/upload-artifact@v7 → v4
- actions/setup-node@v6 → v4
- github/codeql-action v4 → v3

Author: ProfRandom92

.github/workflows/agent-checks.yml

@@ -9,10 +9,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
 
       - name: Set up Python 3.11
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v5
         with:
           python-version: '3.11'
 
@@ -45,7 +45,7 @@ jobs:
 
       - name: Upload agent reports
         if: always()
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@v4
         with:
           name: agent-check-reports
           path: docs/reports/
@@ -55,10 +55,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
 
       - name: Set up Node.js 22
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v4
         with:
           node-version: '22'
 

.github/workflows/ci.yml

@@ -9,15 +9,15 @@ jobs:
   industrial-validation:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v4
 
       - name: Set up Python 3.11
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v5
         with:
           python-version: '3.11'
 
       - name: Set up Node.js 22
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v4
         with:
           node-version: '22'
 
@@ -37,7 +37,7 @@ jobs:
 
       - name: Upload paper replay artifact
         if: always()
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@v4
         with:
           name: paper-replay-results
           path: artifacts/paper_replay_results.json

.github/workflows/codeql.yml

@@ -26,13 +26,13 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4
+        uses: github/codeql-action/init@v3
         with:
           languages: ${{ matrix.language }}
           build-mode: none
 
       - name: Perform CodeQL analysis
-        uses: github/codeql-action/analyze@v4
+        uses: github/codeql-action/analyze@v3