fix(config): preserve custom-provider models maps and metadata through v11->v12 migration (#40573)

Salvaged from #40410; cleaned up, re-verified against main, tests added.

Co-authored-by: rodboev <rodboev@users.noreply.github.com>

hermes_cli/config.py

@@ -3793,6 +3793,42 @@ def _normalize_custom_provider_entry(
     return normalized
 
 
+def _custom_provider_entry_to_provider_config(
+    entry: Any,
+    *,
+    provider_key: str = "",
+) -> Optional[Dict[str, Any]]:
+    """Translate a legacy custom provider entry to the v12 providers shape."""
+    normalized = _normalize_custom_provider_entry(
+        dict(entry) if isinstance(entry, dict) else entry,
+        provider_key=provider_key,
+    )
+    if normalized is None:
+        return None
+
+    provider_entry: Dict[str, Any] = {"api": normalized["base_url"]}
+
+    for field in (
+        "name",
+        "api_key",
+        "key_env",
+        "models",
+        "context_length",
+        "rate_limit_delay",
+        "discover_models",
+        "extra_body",
+    ):
+        if field in normalized:
+            provider_entry[field] = normalized[field]
+
+    if "model" in normalized:
+        provider_entry["default_model"] = normalized["model"]
+    if "api_mode" in normalized:
+        provider_entry["transport"] = normalized["api_mode"]
+
+    return provider_entry
+
+
 def providers_dict_to_custom_providers(providers_dict: Any) -> List[Dict[str, Any]]:
     """Normalize ``providers`` config entries into the legacy custom-provider shape."""
     if not isinstance(providers_dict, dict):
@@ -4299,8 +4335,7 @@ def migrate_config(interactive: bool = True, quiet: bool = False) -> Dict[str, A
                 if not isinstance(entry, dict):
                     continue
                 old_name = entry.get("name", "")
-                old_url = entry.get("base_url", "") or entry.get("url", "") or ""
-                old_key = entry.get("api_key", "")
+                old_url = entry.get("base_url", "") or entry.get("url", "") or entry.get("api", "") or ""
                 if not old_url:
                     continue  # skip entries with no URL
 
@@ -4320,20 +4355,22 @@ def migrate_config(interactive: bool = True, quiet: bool = False) -> Dict[str, A
                         key = f"endpoint-{migrated_count}"
 
                 # Don't overwrite existing entries
-                if key in providers_dict:
-                    key = f"{key}-{migrated_count}"
+                base_key = key
+                suffix = migrated_count
+                while key in providers_dict:
+                    key = f"{base_key}-{suffix}"
+                    suffix += 1
 
-                new_entry = {"api": old_url}
-                if old_name:
-                    new_entry["name"] = old_name
-                if old_key and old_key not in {"no-key", "no-key-required", ""}:
-                    new_entry["api_key"] = old_key
-
-                # Carry over model and api_mode if present
-                if entry.get("model"):
-                    new_entry["default_model"] = entry["model"]
-                if entry.get("api_mode"):
-                    new_entry["transport"] = entry["api_mode"]
+                new_entry = _custom_provider_entry_to_provider_config(
+                    entry,
+                    provider_key=key,
+                )
+                if new_entry is None:
+                    continue
+                if not old_name:
+                    new_entry.pop("name", None)
+                if new_entry.get("api_key") in {"no-key", "no-key-required", ""}:
+                    new_entry.pop("api_key", None)
 
                 providers_dict[key] = new_entry
                 migrated_count += 1