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]

src/generated_scene/analyzer.rs

@@ -109,6 +109,9 @@ pub fn analyze_scene_source_with_hint(
     let expected_domain = meta_content(&html, "sgclaw-expected-domain");
     let entry_script = meta_content(&html, "sgclaw-entry-script");
 
+    // Auto-extract expected_domain from external script URLs if not provided via meta tag
+    let expected_domain = expected_domain.or_else(|| extract_domain_from_external_scripts(&html));
+
     // All fields are optional - generator will use placeholders for missing values
     // This allows third-party scenes without meta tags to be processed
 
@@ -156,3 +159,44 @@ fn attr_value(tag: &str, attr: &str) -> Option<String> {
     let end = rest.find(quote)?;
     Some(rest[..end].to_string())
 }
+
+/// Extract domain from the first external script URL found in HTML.
+///
+/// Looks for `<script src="http://...">` or `<script src="https://...">` tags
+/// and extracts the host:port portion as expected_domain.
+fn extract_domain_from_external_scripts(html: &str) -> Option<String> {
+    for tag in html
+        .split('<')
+        .filter(|fragment| fragment.starts_with("script"))
+    {
+        if let Some(src) = attr_value(tag, "src") {
+            // Check if it's an external URL (http:// or https://)
+            if src.starts_with("http://") || src.starts_with("https://") {
+                // Extract domain (host:port) from URL
+                if let Some(domain) = extract_domain_from_url(&src) {
+                    return Some(domain);
+                }
+            }
+        }
+    }
+    None
+}
+
+/// Extract domain (host:port) from a URL string.
+fn extract_domain_from_url(url: &str) -> Option<String> {
+    // Remove protocol prefix
+    let rest = url
+        .strip_prefix("http://")
+        .or_else(|| url.strip_prefix("https://"))?;
+    
+    // Find the end of domain (first '/' or end of string)
+    let domain_end = rest.find('/').unwrap_or(rest.len());
+    let domain = &rest[..domain_end];
+    
+    // Return non-empty domain
+    if domain.is_empty() {
+        None
+    } else {
+        Some(domain.to_string())
+    }
+}