diff --git a/studio/setup.ps1 b/studio/setup.ps1
index e9a211eb45..f797313964 100644
--- a/studio/setup.ps1
+++ b/studio/setup.ps1
@@ -757,14 +757,20 @@ if ($IsPipInstall) {
     Write-Host "[OK] Running from pip install - frontend already bundled, skipping build" -ForegroundColor Green
 } elseif (Test-Path $DistDir) {
     $DistTime = (Get-Item $DistDir).LastWriteTime
-    # Check src/ and public/ recursively
-    $NewerFile = Get-ChildItem -Path $FrontendDir -Include "src","public" -Directory -ErrorAction SilentlyContinue |
-        ForEach-Object { Get-ChildItem -Path $_.FullName -Recurse -File -ErrorAction SilentlyContinue } |
-        Where-Object { $_.LastWriteTime -gt $DistTime } | Select-Object -First 1
-    # Also check top-level config files (package.json, vite.config.ts, etc.)
+    $NewerFile = $null
+    # Check src/ and public/ recursively (probe paths directly, not via -Include)
+    foreach ($subDir in @("src", "public")) {
+        $subPath = Join-Path $FrontendDir $subDir
+        if (Test-Path $subPath) {
+            $NewerFile = Get-ChildItem -Path $subPath -Recurse -File -ErrorAction SilentlyContinue |
+                Where-Object { $_.LastWriteTime -gt $DistTime } | Select-Object -First 1
+            if ($NewerFile) { break }
+        }
+    }
+    # Also check ALL top-level files (package.json, index.html, bun.lock, configs, etc.)
     if (-not $NewerFile) {
         $NewerFile = Get-ChildItem -Path $FrontendDir -File -ErrorAction SilentlyContinue |
-            Where-Object { $_.Name -match '\.(json|ts|js|mjs)$' -and $_.LastWriteTime -gt $DistTime } |
+            Where-Object { $_.LastWriteTime -gt $DistTime } |
             Select-Object -First 1
     }
     if (-not $NewerFile) {
diff --git a/studio/setup.sh b/studio/setup.sh
index 2c93d57f78..c0694df1aa 100755
--- a/studio/setup.sh
+++ b/studio/setup.sh
@@ -47,8 +47,9 @@ fi
 # and upgrades/pulls (source newer than dist/ triggers rebuild).
 _NEED_FRONTEND_BUILD=true
 if [ -d "$SCRIPT_DIR/frontend/dist" ]; then
-    _changed=$(find "$SCRIPT_DIR/frontend" -maxdepth 1 -name "*.json" -o -name "*.ts" -o -name "*.js" -o -name "*.mjs" | \
-        xargs -r find -newer "$SCRIPT_DIR/frontend/dist" 2>/dev/null | head -1)
+    # Check top-level config files (package.json, vite.config.ts, index.html, bun.lock, etc.)
+    _changed=$(find "$SCRIPT_DIR/frontend" -maxdepth 1 -type f -newer "$SCRIPT_DIR/frontend/dist" 2>/dev/null | head -1)
+    # Check src/ and public/ recursively
     if [ -z "$_changed" ]; then
         _changed=$(find "$SCRIPT_DIR/frontend/src" "$SCRIPT_DIR/frontend/public" \
             -type f -newer "$SCRIPT_DIR/frontend/dist" 2>/dev/null | head -1)
@@ -162,8 +163,8 @@ echo "✅ Frontend built to frontend/dist"
 
 fi  # end frontend build check
 
-# ── oxc-validator runtime (always install, independent of frontend build) ──
-if [ -d "$SCRIPT_DIR/backend/core/data_recipe/oxc-validator" ]; then
+# ── oxc-validator runtime (needs npm -- skip if not available) ──
+if [ -d "$SCRIPT_DIR/backend/core/data_recipe/oxc-validator" ] && command -v npm &>/dev/null; then
     cd "$SCRIPT_DIR/backend/core/data_recipe/oxc-validator"
     run_quiet "npm install (oxc validator runtime)" npm install
     cd "$SCRIPT_DIR"