fix: remove last-provider deletion restriction for OMO/OMO Slim plugins

OMO and OMO Slim are OpenCode plugins, not standalone apps — users
should be able to fully remove them. Remove the count-based guard that
prevented deleting the last active provider, and clean up the now-unused
provider-count API surface across the full stack.

src/components/providers/ProviderActions.tsx

@@ -24,7 +24,6 @@ interface ProviderActionsProps {
   isTesting?: boolean;
   isProxyTakeover?: boolean;
   isOmo?: boolean;
-  isLastOmo?: boolean;
   onSwitch: () => void;
   onEdit: () => void;
   onDuplicate: () => void;
@@ -49,7 +48,6 @@ export function ProviderActions({
   isTesting: _isTesting, // Hidden: stream check feature disabled
   isProxyTakeover = false,
   isOmo = false,
-  isLastOmo = false,
   onSwitch,
   onEdit,
   onDuplicate,
@@ -192,11 +190,7 @@ export function ProviderActions({
 
   const buttonState = getMainButtonState();
 
-  const canDelete = isOmo
-    ? !(isLastOmo && isCurrent)
-    : isAdditiveMode
-      ? true
-      : !isCurrent;
+  const canDelete = isOmo || isAdditiveMode ? true : !isCurrent;
 
   return (
     <div className="flex items-center gap-1.5">

src/components/providers/ProviderCard.tsx

@@ -28,9 +28,7 @@ interface ProviderCardProps {
   appId: AppId;
   isInConfig?: boolean; // OpenCode: 是否已添加到 opencode.json
   isOmo?: boolean;
-  isLastOmo?: boolean;
   isOmoSlim?: boolean;
-  isLastOmoSlim?: boolean;
   onSwitch: (provider: Provider) => void;
   onEdit: (provider: Provider) => void;
   onDelete: (provider: Provider) => void;
@@ -94,9 +92,7 @@ export function ProviderCard({
   appId,
   isInConfig = true,
   isOmo = false,
-  isLastOmo = false,
   isOmoSlim = false,
-  isLastOmoSlim = false,
   onSwitch,
   onEdit,
   onDelete,
@@ -125,7 +121,6 @@ export function ProviderCard({
 
   // OMO and OMO Slim share the same card behavior
   const isAnyOmo = isOmo || isOmoSlim;
-  const isLastAnyOmo = isOmo ? isLastOmo : isLastOmoSlim;
   const handleDisableAnyOmo = isOmoSlim ? onDisableOmoSlim : onDisableOmo;
 
   const { data: health } = useProviderHealth(provider.id, appId);
@@ -390,7 +385,6 @@ export function ProviderCard({
               isTesting={isTesting}
               isProxyTakeover={isProxyTakeover}
               isOmo={isAnyOmo}
-              isLastOmo={isLastAnyOmo}
               onSwitch={() => onSwitch(provider)}
               onEdit={() => onEdit(provider)}
               onDuplicate={() => onDuplicate(provider)}

src/components/providers/ProviderList.tsx

@@ -36,9 +36,7 @@ import {
 } from "@/lib/query/failover";
 import {
   useCurrentOmoProviderId,
-  useOmoProviderCount,
   useCurrentOmoSlimProviderId,
-  useOmoSlimProviderCount,
 } from "@/lib/query/omo";
 import { useCallback } from "react";
 import { Input } from "@/components/ui/input";
@@ -142,9 +140,7 @@ export function ProviderList({
 
   const isOpenCode = appId === "opencode";
   const { data: currentOmoId } = useCurrentOmoProviderId(isOpenCode);
-  const { data: omoProviderCount } = useOmoProviderCount(isOpenCode);
   const { data: currentOmoSlimId } = useCurrentOmoSlimProviderId(isOpenCode);
-  const { data: omoSlimProviderCount } = useOmoSlimProviderCount(isOpenCode);
 
   const getFailoverPriority = useCallback(
     (providerId: string): number | undefined => {
@@ -293,15 +289,7 @@ export function ProviderList({
                 appId={appId}
                 isInConfig={isProviderInConfig(provider.id)}
                 isOmo={isOmo}
-                isLastOmo={
-                  isOmo && (omoProviderCount ?? 0) <= 1 && isOmoCurrent
-                }
                 isOmoSlim={isOmoSlim}
-                isLastOmoSlim={
-                  isOmoSlim &&
-                  (omoSlimProviderCount ?? 0) <= 1 &&
-                  isOmoSlimCurrent
-                }
                 onSwitch={onSwitch}
                 onEdit={onEdit}
                 onDelete={onDelete}
@@ -420,9 +408,7 @@ interface SortableProviderCardProps {
   appId: AppId;
   isInConfig: boolean;
   isOmo: boolean;
-  isLastOmo: boolean;
   isOmoSlim: boolean;
-  isLastOmoSlim: boolean;
   onSwitch: (provider: Provider) => void;
   onEdit: (provider: Provider) => void;
   onDelete: (provider: Provider) => void;
@@ -453,9 +439,7 @@ function SortableProviderCard({
   appId,
   isInConfig,
   isOmo,
-  isLastOmo,
   isOmoSlim,
-  isLastOmoSlim,
   onSwitch,
   onEdit,
   onDelete,
@@ -500,9 +484,7 @@ function SortableProviderCard({
         appId={appId}
         isInConfig={isInConfig}
         isOmo={isOmo}
-        isLastOmo={isLastOmo}
         isOmoSlim={isOmoSlim}
-        isLastOmoSlim={isLastOmoSlim}
         onSwitch={onSwitch}
         onEdit={onEdit}
         onDelete={onDelete}