Fix Test Connection for External tokens, ClearFindingsAction BGT thread

Author: Offensive 360

src/main/kotlin/com/offensive360/sast/actions/ClearFindingsAction.kt

@@ -1,10 +1,13 @@
 package com.offensive360.sast.actions
 
+import com.intellij.openapi.actionSystem.ActionUpdateThread
 import com.intellij.openapi.actionSystem.AnAction
 import com.intellij.openapi.actionSystem.AnActionEvent
 import com.offensive360.sast.toolwindow.SecurityFindingsService
 
 class ClearFindingsAction : AnAction() {
+    override fun getActionUpdateThread() = ActionUpdateThread.BGT
+
     override fun actionPerformed(e: AnActionEvent) {
         val project = e.project ?: return
         SecurityFindingsService.getInstance(project).clearFindings()

src/main/kotlin/com/offensive360/sast/settings/O360Configurable.kt

@@ -112,7 +112,8 @@ class O360Configurable : Configurable {
         }
 
         val allowSelfSigned = allowSelfSignedCheckbox.isSelected
-        val healthUrl = "$endpoint/app/api/HealthCheck"
+        // Use ExternalScan endpoint for validation — HealthCheck returns 403 for External tokens
+        val healthUrl = "$endpoint/app/api/ExternalScan/scanQueuePosition"
 
         testConnectionButton.isEnabled = false
         testConnectionButton.text = "Testing\u2026"