feat(desktop): add preview url allowlist (normalize_preview_url)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

desktop/src-tauri/src/lib.rs

@@ -217,6 +217,8 @@ mod macos_notifications {
     }
 }
 
+mod webview_panel;
+
 const SERVER_STARTUP_LOG_LIMIT: usize = 80;
 const SERVER_BIND_HOST: &str = "0.0.0.0";
 const SERVER_CONTROL_HOST: &str = "127.0.0.1";

desktop/src-tauri/src/webview_panel.rs

@@ -0,0 +1,36 @@
+/// 仅允许 http/https；其它（file:、javascript: 等）拒绝。返回规范化后的 url 字符串。
+pub fn normalize_preview_url(input: &str) -> Result<String, String> {
+    let trimmed = input.trim();
+    if trimmed.is_empty() {
+        return Err("empty url".to_string());
+    }
+    let lower = trimmed.to_ascii_lowercase();
+    if lower.starts_with("http://") || lower.starts_with("https://") {
+        Ok(trimmed.to_string())
+    } else {
+        Err(format!("unsupported url scheme: {trimmed}"))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn accepts_http_and_https() {
+        assert_eq!(normalize_preview_url("http://localhost:5173/").unwrap(), "http://localhost:5173/");
+        assert_eq!(normalize_preview_url("https://example.com").unwrap(), "https://example.com");
+    }
+
+    #[test]
+    fn trims_whitespace() {
+        assert_eq!(normalize_preview_url("  http://127.0.0.1:8080  ").unwrap(), "http://127.0.0.1:8080");
+    }
+
+    #[test]
+    fn rejects_non_http_schemes() {
+        assert!(normalize_preview_url("file:///etc/passwd").is_err());
+        assert!(normalize_preview_url("javascript:alert(1)").is_err());
+        assert!(normalize_preview_url("").is_err());
+    }
+}