feat: respect --quiet flag in MCP client logging

- Add _is_quiet property to MCP Client class
- Suppress INFO/DEBUG logs when MCP server runs with --quiet
- Still show ERROR/WARNING logs in quiet mode
- Parse nerve-style log formats for proper log levels
- Improves UX when orchestrating multiple MCP agents

This change allows cleaner output when using MCP servers in
orchestration scenarios, while preserving important error
information.

Author: nickpending

nerve/tools/mcp/client.py

@@ -42,16 +42,38 @@ def __init__(self, name: str, server: Configuration.MCPServer, working_dir: path
         self._exit_stack = AsyncExitStack()
         self._tools: list[Tool] = []
         self._client_context: t.Any = None
+        # Check if this MCP server should run in quiet mode
+        self._is_quiet = "--quiet" in (server.args or [])
 
     async def _logging_callback(
         self,
         params: mcp_types.LoggingMessageNotificationParams,
     ) -> None:
         line = str(params.data)
-        # parts = line.split("]", 2)
-        # line = parts[1].strip() if len(parts) > 1 else line  # remove timestamp
-        # line = line.replace(str(params.level).upper(), "").strip()  # remove level
-        getattr(logger, str(params.level))(f"<{self.name}> {line}")
+        
+        # In quiet mode, suppress verbose output but still show errors/warnings
+        if self._is_quiet:
+            # Parse the actual log level from nerve-formatted log lines
+            if "] ERROR " in line or "] WARNING " in line:
+                # Show errors and warnings even in quiet mode
+                pass
+            elif "] INFO " in line or "] DEBUG " in line or "🧠" in line or "📊" in line or "🛠️" in line:
+                # Suppress informational logs and tool output in quiet mode
+                return
+            else:
+                # For unstructured output (like tool results), suppress in quiet mode
+                return
+        
+        # Determine appropriate log level based on content
+        if "] ERROR " in line:
+            logger.error(f"<{self.name}> {line}")
+        elif "] WARNING " in line:
+            logger.warning(f"<{self.name}> {line}")
+        elif "] INFO " in line:
+            logger.info(f"<{self.name}> {line}")
+        else:
+            # Default to the level provided by MCP protocol
+            getattr(logger, str(params.level))(f"<{self.name}> {line}")
 
     @asynccontextmanager
     async def _safe_stdio_context(