feat(config): add support for disabling OpenAI compatibility providers

- Introduced a `Disabled` flag to OpenAI compatibility configurations.
- Updated routing, auth selection, and API handling logic to respect the `Disabled` state.
- Extended relevant APIs, YAML configurations, and data structures to include the `Disabled` field.
- Adjusted all relevant loops and filters to skip disabled providers.

Closes: #3060 #3059 #2977

internal/api/handlers/management/config_auth_index.go

@@ -36,6 +36,7 @@ type openAICompatibilityAPIKeyWithAuthIndex struct {
 type openAICompatibilityWithAuthIndex struct {
 	Name          string                                   `json:"name"`
 	Priority      int                                      `json:"priority,omitempty"`
+	Disabled      bool                                     `json:"disabled"`
 	Prefix        string                                   `json:"prefix,omitempty"`
 	BaseURL       string                                   `json:"base-url"`
 	APIKeyEntries []openAICompatibilityAPIKeyWithAuthIndex `json:"api-key-entries,omitempty"`
@@ -215,6 +216,7 @@ func (h *Handler) openAICompatibilityWithAuthIndex() []openAICompatibilityWithAu
 		response := openAICompatibilityWithAuthIndex{
 			Name:      entry.Name,
 			Priority:  entry.Priority,
+			Disabled:  entry.Disabled,
 			Prefix:    entry.Prefix,
 			BaseURL:   entry.BaseURL,
 			Models:    entry.Models,