feat: auto-extract expected_domain from external script URLs

When HTML has no sgclaw-expected-domain meta tag, analyzer now scans
for external script URLs (http:// or https://) and extracts the
domain (host:port) as expected_domain.

Example:
  <script src="http://25.215.213.128:18080/a_js/YPTAPI.js"></script>
  → expected_domain = "25.215.213.128:18080"

This reduces manual editing required for third-party scenes.

🤖 Generated with [Qoder][https://qoder.com]

tests/scene_generator_test.rs

@@ -166,3 +166,20 @@ fn generator_emits_monitoring_template() {
     // 监测类不应该有 org/period resolver
     assert!(!generated_manifest.contains("resolver = \"dictionary_entity\""));
 }
+
+#[test]
+fn analyzer_extracts_domain_from_external_script() {
+    // external_script fixture has no expected_domain meta tag,
+    // but has an external script URL that should be auto-extracted
+    let analysis = analyze_scene_source(Path::new(
+        "tests/fixtures/generated_scene/external_script",
+    ))
+    .unwrap();
+
+    assert_eq!(analysis.scene_kind, SceneKind::ReportCollection);
+    // Should auto-extract "25.215.213.128:18080" from script src
+    assert_eq!(
+        analysis.bootstrap.expected_domain.as_deref(),
+        Some("25.215.213.128:18080")
+    );
+}