feat(ai): add Xiaomi MiMo provider, ZAI as last-resort fallback

Add MiMo-V2.5-Pro from Xiaomi Token Plan as a new AI provider with
base URL https://token-plan-ams.xiaomimimo.com/v1. The /model change
command now switches between MiniMax and MiMo only. ZAI is always
placed last in the fallback chain as the provider of ultimate resort.
Config panel shows MiniMax and MiMo cards.

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

internal/api/handlers_info.go

@@ -530,6 +530,11 @@ func (s *Server) handleProvidersQuota(w http.ResponseWriter, r *http.Request) {
 					}
 				}
 			}
+		case "mimo":
+			q.Healthy = p.APIKey != ""
+			if p.APIKey == "" {
+				q.Error = "no API key"
+			}
 		case "claude", "anthropic":
 			// Claude Code n'a pas d'API externe, vérifier l'installation
 			claudePath := "/usr/bin/claude"

internal/config/config.go

@@ -269,6 +269,12 @@ func Default() *MuyueConfig {
 			BaseURL: "https://api.minimax.io/v1",
 			Active:  true,
 		},
+		{
+			Name:    "mimo",
+			Model:   "MiMo-V2.5-Pro",
+			BaseURL: "https://token-plan-ams.xiaomimimo.com/v1",
+			Active:  false,
+		},
 		{
 			Name:    "zai",
 			Model:   "glm",

internal/orchestrator/orchestrator.go

@@ -476,6 +476,8 @@ func getProviderBaseURL(name string) string {
 		return "https://api.openai.com/v1"
 	case "zai":
 		return "https://api.z.ai/v1"
+	case "mimo":
+		return "https://token-plan-ams.xiaomimimo.com/v1"
 	default:
 		return ""
 	}
@@ -503,11 +505,19 @@ func (o *Orchestrator) sendWithFallback(reqBody ChatRequest, baseURLOverride str
 	if o.provider != nil {
 		providerOrder = append(providerOrder, o.provider)
 	}
+	var zaiProvider *config.AIProvider
 	for _, p := range providers {
 		if o.provider == nil || p.Name != o.provider.Name {
-			providerOrder = append(providerOrder, p)
+			if p.Name == "zai" {
+				zaiProvider = p
+			} else {
+				providerOrder = append(providerOrder, p)
+			}
 		}
 	}
+	if zaiProvider != nil {
+		providerOrder = append(providerOrder, zaiProvider)
+	}
 
 	var lastErr error
 	var triedProviders []string