fix(ci): restore stable hex check and satisfy browser clippy gate

src/security/secrets.rs

@@ -241,7 +241,7 @@ fn hex_encode(data: &[u8]) -> String {
 
 /// Hex-decode a hex string to bytes.
 fn hex_decode(hex: &str) -> Result<Vec<u8>> {
-    if !hex.len().is_multiple_of(2) {
+    if (hex.len() & 1) != 0 {
         anyhow::bail!("Hex string has odd length");
     }
     (0..hex.len())

src/tools/browser.rs

@@ -365,6 +365,7 @@ impl BrowserTool {
     }
 }
 
+#[allow(clippy::too_many_lines)]
 #[async_trait]
 impl Tool for BrowserTool {
     fn name(&self) -> &str {