tabs and app mode signals (#450)

Usage example - Conditional Rendering Based on App Mode:
```typescript
import { appMode } from "~/signals";

function ConditionalComponent() {
  return (
    <div className="app-container">
      {/* Show/hide components based on current mode */}
      {appMode.value === 'image' && (
        <div className="image-tools">
          <h3>Image Mode Tools</h3>
        </div>
      )}
      
      {appMode.value === 'edit' && (
        <div className="edit-tools">
          <h3>Edit Mode Tools</h3>
        </div>
      )}
  );
}
```

frontend/realtime/src/components/features/ToolbarTopLeft/index.tsx

@@ -1,17 +1,43 @@
 import { twMerge } from "tailwind-merge";
+import { TabSelector, TabItem } from "~/components/ui/TabSelector";
+import { useComputed } from "@preact/signals-react";
+import { appMode, dispatchUiEvents } from "~/signals";
 
 // import { paperWrapperStyles } from "~/components/styles";
 // import { faPlus, faQuestion } from "@fortawesome/pro-solid-svg-icons";
 // import { ToolbarButton } from "~/components/features/ToolbarButton";
 
 export const ToolbarTopLeft = () => {
+  // Use the appMode signal directly with useComputed for reactivity - active tab sets the app mode
+  const activeTab = useComputed(() => appMode.value);
+
+  const tabs: TabItem[] = [
+    { id: "image", label: "Image" },
+    { id: "edit", label: "Edit" },
+    // { id: "video", label: "Video" },
+  ];
+
+  const handleTabChange = (tabId: string) => {
+    // Update the global signal
+    dispatchUiEvents.changeAppMode(tabId as "image" | "edit");
+  };
+
+  console.log(appMode.value);
+
   return (
-    <div className={twMerge("z-20 flex h-fit w-fit items-center gap-1")}>
+    <div className={twMerge("z-20 flex h-fit w-fit items-center gap-8 px-4")}>
       <img
         src="/brand/mira-logo.png"
         alt="logo"
         className="h-[30px] select-none pb-1"
       />
+
+      <TabSelector
+        tabs={tabs}
+        activeTab={activeTab.value}
+        onTabChange={handleTabChange}
+      />
+
       {/* <ToolbarButton icon={faPlus}>
         <span className="font-semibold">New Board</span>
       </ToolbarButton>

frontend/realtime/src/components/ui/TabSelector.tsx

@@ -0,0 +1,82 @@
+import React, { useRef, useEffect, useState } from "react";
+import { Tab, TabGroup, TabList } from "@headlessui/react";
+import { twMerge } from "tailwind-merge";
+
+export interface TabItem {
+  id: string;
+  label: string;
+}
+
+interface TabSelectorProps {
+  tabs: TabItem[];
+  activeTab: string;
+  onTabChange: (tabId: string) => void;
+  className?: string;
+}
+
+export const TabSelector: React.FC<TabSelectorProps> = ({
+  tabs,
+  activeTab,
+  onTabChange,
+  className,
+}) => {
+  // Find the index of the active tab
+  const selectedIndex = tabs.findIndex((tab) => tab.id === activeTab);
+  const tabsRef = useRef<(HTMLElement | null)[]>([]);
+  const [indicatorStyle, setIndicatorStyle] = useState({
+    left: 0,
+    width: 0,
+  });
+
+  // Handle tab change
+  const handleTabChange = (index: number) => {
+    onTabChange(tabs[index].id);
+  };
+
+  // Update the indicator position when the selected tab changes
+  useEffect(() => {
+    if (selectedIndex >= 0 && tabsRef.current[selectedIndex]) {
+      const currentTab = tabsRef.current[selectedIndex];
+      if (currentTab) {
+        setIndicatorStyle({
+          left: currentTab.offsetLeft,
+          width: currentTab.offsetWidth,
+        });
+      }
+    }
+  }, [selectedIndex, tabs]);
+
+  return (
+    <TabGroup
+      selectedIndex={selectedIndex}
+      onChange={handleTabChange}
+      className={twMerge("w-full", className)}
+    >
+      <TabList className="glass relative inline-flex min-w-fit overflow-x-auto rounded-lg p-1 shadow-lg">
+        {/* Animated indicator */}
+        <div
+          className="absolute top-1 z-10 h-[calc(100%-8px)] rounded-md border-2 border-primary bg-primary/30 transition-all duration-300 ease-in-out"
+          style={{
+            left: indicatorStyle.left,
+            width: indicatorStyle.width,
+          }}
+        />
+
+        {tabs.map((tab, index) => (
+          <Tab
+            key={tab.id}
+            ref={(el) => (tabsRef.current[index] = el)}
+            className={({ selected }) =>
+              twMerge(
+                "relative z-20 mx-0.5 min-w-max rounded-md border-2 border-transparent px-4 py-1 text-center font-semibold transition-all duration-300 ease-in-out",
+                selected ? "text-white" : "text-gray-300 hover:text-white",
+              )
+            }
+          >
+            {tab.label}
+          </Tab>
+        ))}
+      </TabList>
+    </TabGroup>
+  );
+};

frontend/realtime/src/components/ui/index.ts

@@ -8,6 +8,7 @@ export * from "./PanelRight";
 export * from "./Slider";
 export * from "./Spinner";
 export * from "./Switches";
+export * from "./TabSelector";
 export * from "./TextArea";
 export * from "./TextEditor";
 export * from "./Tooltip";

frontend/realtime/src/signals/uiEvents/appMode.ts

@@ -0,0 +1,38 @@
+import { signal, effect } from "@preact/signals-core";
+
+// this is to control the app mode - BFlat
+
+// Define the app mode types
+export type AppModeType = "image" | "edit";
+
+// Create a signal for the current app mode
+export const appMode = signal<AppModeType>("image");
+
+// Create a function to change the app mode
+export const changeAppMode = (mode: AppModeType) => {
+  appMode.value = mode;
+};
+
+// Store callbacks for mode changes
+const callbacks: ((mode: AppModeType) => void)[] = [];
+
+// Set up an effect to notify callbacks when the mode changes
+effect(() => {
+  const currentMode = appMode.value;
+  callbacks.forEach((callback) => callback(currentMode));
+});
+
+// Export an event handler for components to use
+export const appModeEvents = {
+  onChange: (callback: (mode: AppModeType) => void) => {
+    callbacks.push(callback);
+
+    // Return a function to unsubscribe
+    return () => {
+      const index = callbacks.indexOf(callback);
+      if (index !== -1) {
+        callbacks.splice(index, 1);
+      }
+    };
+  },
+};

frontend/realtime/src/signals/uiEvents/index.ts

@@ -36,6 +36,7 @@ import {
   dispatchers as modelSelectionDispatchers,
   events as modelSelectionEvents,
 } from "./modelSelection";
+import { appMode, changeAppMode, appModeEvents } from "./appMode";
 
 export const uiEvents = {
   ...addMediaEvents,
@@ -49,6 +50,7 @@ export const uiEvents = {
   promptEvents: promptEvents,
   loadingIndicator: loadingIndicatorEvents,
   modelSelection: modelSelectionEvents,
+  appMode: appModeEvents,
 };
 export const dispatchUiEvents = {
   ...addMediaDispatchers,
@@ -62,4 +64,7 @@ export const dispatchUiEvents = {
   promptSettings: promptDispatchers,
   loadingIndicator: loadingIndicatorDispatchers,
   modelSelection: modelSelectionDispatchers,
+  changeAppMode,
 };
+
+export { appMode };