feat(index): add provider cache missing warning toast

Show warning toast when hasConnectedProvidersCache() returns false,
indicating model filtering is disabled. Prompts user to restart
OpenCode for full functionality.

src/index.ts

@@ -78,7 +78,7 @@ import { SkillMcpManager } from "./features/skill-mcp-manager";
 import { initTaskToastManager } from "./features/task-toast-manager";
 import { TmuxSessionManager } from "./features/tmux-subagent";
 import { type HookName } from "./config";
-import { log, detectExternalNotificationPlugin, getNotificationConflictWarning, resetMessageCursor, includesCaseInsensitive } from "./shared";
+import { log, detectExternalNotificationPlugin, getNotificationConflictWarning, resetMessageCursor, includesCaseInsensitive, hasConnectedProvidersCache } from "./shared";
 import { loadPluginConfig } from "./plugin-config";
 import { createModelCacheState, getModelLimit } from "./plugin-state";
 import { createConfigHandler } from "./plugin-handlers";
@@ -398,6 +398,17 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
       await autoSlashCommand?.["chat.message"]?.(input, output);
       await startWork?.["chat.message"]?.(input, output);
 
+      if (!hasConnectedProvidersCache()) {
+        ctx.client.tui.showToast({
+          body: {
+            title: "⚠️ Provider Cache Missing",
+            message: "Model filtering disabled. RESTART OpenCode to enable full functionality.",
+            variant: "warning" as const,
+            duration: 6000,
+          },
+        }).catch(() => {});
+      }
+
       if (ralphLoop) {
         const parts = (
           output as { parts?: Array<{ type: string; text?: string }> }