fix: complete ensure_ascii=False and UTF-8 encoding migration

nanobot/providers/litellm_provider.py

@@ -88,10 +88,21 @@ class LiteLLMProvider(LLMProvider):
         # Standard mode: auto-prefix for known providers
         spec = find_by_model(model)
         if spec and spec.litellm_prefix:
+            model = self._canonicalize_explicit_prefix(model, spec.name, spec.litellm_prefix)
             if not any(model.startswith(s) for s in spec.skip_prefixes):
                 model = f"{spec.litellm_prefix}/{model}"
-        
+
         return model
+
+    @staticmethod
+    def _canonicalize_explicit_prefix(model: str, spec_name: str, canonical_prefix: str) -> str:
+        """Normalize explicit provider prefixes like `github-copilot/...`."""
+        if "/" not in model:
+            return model
+        prefix, remainder = model.split("/", 1)
+        if prefix.lower().replace("-", "_") != spec_name:
+            return model
+        return f"{canonical_prefix}/{remainder}"
     
     def _apply_model_overrides(self, model: str, kwargs: dict[str, Any]) -> None:
         """Apply model-specific parameter overrides from the registry."""

nanobot/providers/openai_codex_provider.py

@@ -80,7 +80,7 @@ class OpenAICodexProvider(LLMProvider):
 
 
 def _strip_model_prefix(model: str) -> str:
-    if model.startswith("openai-codex/"):
+    if model.startswith("openai-codex/") or model.startswith("openai_codex/"):
         return model.split("/", 1)[1]
     return model
 
@@ -176,7 +176,7 @@ def _convert_messages(messages: list[dict[str, Any]]) -> tuple[str, list[dict[st
 
         if role == "tool":
             call_id, _ = _split_tool_call_id(msg.get("tool_call_id"))
-            output_text = content if isinstance(content, str) else json.dumps(content)
+            output_text = content if isinstance(content, str) else json.dumps(content, ensure_ascii=False)
             input_items.append(
                 {
                     "type": "function_call_output",

nanobot/providers/registry.py

@@ -384,10 +384,18 @@ def find_by_model(model: str) -> ProviderSpec | None:
     """Match a standard provider by model-name keyword (case-insensitive).
     Skips gateways/local — those are matched by api_key/api_base instead."""
     model_lower = model.lower()
-    for spec in PROVIDERS:
-        if spec.is_gateway or spec.is_local:
-            continue
-        if any(kw in model_lower for kw in spec.keywords):
+    model_normalized = model_lower.replace("-", "_")
+    model_prefix = model_lower.split("/", 1)[0] if "/" in model_lower else ""
+    normalized_prefix = model_prefix.replace("-", "_")
+    std_specs = [s for s in PROVIDERS if not s.is_gateway and not s.is_local]
+
+    # Prefer explicit provider prefix — prevents `github-copilot/...codex` matching openai_codex.
+    for spec in std_specs:
+        if model_prefix and normalized_prefix == spec.name:
+            return spec
+
+    for spec in std_specs:
+        if any(kw in model_lower or kw.replace("-", "_") in model_normalized for kw in spec.keywords):
             return spec
     return None
 

nanobot/providers/transcription.py

@@ -35,7 +35,7 @@ class GroqTranscriptionProvider:
         
         path = Path(file_path)
         if not path.exists():
-            logger.error(f"Audio file not found: {file_path}")
+            logger.error("Audio file not found: {}", file_path)
             return ""
         
         try:
@@ -61,5 +61,5 @@ class GroqTranscriptionProvider:
                     return data.get("text", "")
                     
         except Exception as e:
-            logger.error(f"Groq transcription error: {e}")
+            logger.error("Groq transcription error: {}", e)
             return ""