🔨 **test(test_real_detection): Raise error for non-memory model load failures**

Update test to ensure non-memory errors raise `DetectError` instead of falling back to a smaller model.

📝 **docs(README): Clarify fallback behavior and add language code mapping guide**
Explain conditions for model fallback and provide guidance on mapping language codes to English names using `langcodes`.

Author: sudoskys

src/fast_langdetect/infer.py

@@ -262,7 +262,7 @@ def _preprocess_text(self, text: str) -> str:
 
         # Auto-truncate overly long input if configured
         if self.config.max_input_length is not None and len(text) > self.config.max_input_length:
-            logger.warning(
+            logger.info(
                 f"fast-langdetect: Truncating input from {len(text)} to {self.config.max_input_length} characters; may reduce accuracy."
             )
             text = text[: self.config.max_input_length]