feat: add log level configuration and validation

src/cordra_mcp/config.py

@@ -1,6 +1,6 @@
 """Configuration settings for the MCP Cordra server."""
 
-from pydantic import Field
+from pydantic import Field, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
@@ -26,3 +26,21 @@ class CordraConfig(BaseSettings):
         default=True, description="Whether to verify SSL certificates"
     )
     timeout: int = Field(default=30, description="Request timeout in seconds")
+    log_level: str = Field(
+        default="INFO",
+        description="Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)",
+        validation_alias="LOGLEVEL",
+    )
+
+    @field_validator("log_level", mode="before")
+    @classmethod
+    def validate_log_level(cls, v: str) -> str:
+        """Validate that log_level is a standard logging level."""
+        level_str = str(v).upper().strip()
+        valid_levels = {"DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"}
+
+        if level_str not in valid_levels:
+            raise ValueError(
+                f"Invalid log level '{v}'. Must be one of: {', '.join(valid_levels)}"
+            )
+        return level_str