feat: enhance safety filters for shell commands by normalizing ANSI-C quoting

src/app/lsp/client.rs

@@ -202,10 +202,18 @@ impl LspClient {
                 break;
             }
             if let Some(len_str) = trimmed.strip_prefix("Content-Length: ") {
-                content_length = Some(
-                    len_str.trim().parse::<usize>()
-                        .map_err(|e| anyhow::anyhow!("invalid Content-Length '{}': {}", len_str.trim(), e))?,
-                );
+                let length: usize = len_str.trim().parse::<usize>()
+                    .map_err(|e| anyhow::anyhow!("invalid Content-Length '{}': {}", len_str.trim(), e))?;
+                // Cap Content-Length at 64 MiB to prevent OOM from a
+                // malicious or misconfigured LSP server (CWE-400).
+                const MAX_CONTENT_LENGTH: usize = 64 * 1024 * 1024;
+                if length > MAX_CONTENT_LENGTH {
+                    anyhow::bail!(
+                        "Content-Length {} exceeds maximum allowed size of {} bytes",
+                        length, MAX_CONTENT_LENGTH,
+                    );
+                }
+                content_length = Some(length);
             }
         }