ci: consolidate workflows, harden security, and clean up .github

.github/scripts/check-code.ps1

@@ -48,13 +48,14 @@ try {
     exit 1
 }
 
-# Type check with mypy (non-blocking)
+# Type check with mypy
 Write-Host "🔬 Type checking with mypy..." -ForegroundColor Yellow
 try {
-    mypy semantica/ 2>&1 | Out-Null
+    mypy semantica/
     Write-Host "✅ mypy check passed" -ForegroundColor Green
 } catch {
-    Write-Host "⚠️  Type checking issues found (non-blocking)" -ForegroundColor Yellow
+    Write-Host "❌ Type checking issues found" -ForegroundColor Red
+    exit 1
 }
 
 Write-Host ""

.github/scripts/check-code.sh

@@ -46,12 +46,13 @@ else
     exit 1
 fi
 
-# Type check with mypy (non-blocking)
+# Type check with mypy
 echo "🔬 Type checking with mypy..."
-if mypy semantica/ 2>/dev/null; then
+if mypy semantica/; then
     echo "✅ mypy check passed"
 else
-    echo "⚠️  Type checking issues found (non-blocking)"
+    echo "❌ Type checking issues found"
+    exit 1
 fi
 
 echo ""