feat(playground): enhance SSE debugging and add image paste support with i18n

- Add SSEViewer component for interactive SSE message inspection
  * Display SSE data stream with collapsible panels
  * Show parsed JSON with syntax highlighting
  * Display key information badges (content, tokens, finish reason)
  * Support copy individual or all SSE messages
  * Show error messages with detailed information

- Support Ctrl+V to paste images in chat input
  * Enable image paste in CustomInputRender component
  * Auto-detect and add pasted images to image list
  * Show toast notifications for paste results

- Add complete i18n support for 6 languages
  * Chinese (zh): Complete translations
  * English (en): Complete translations
  * Japanese (ja): Add 28 new translations
  * French (fr): Add 28 new translations
  * Russian (ru): Add 28 new translations
  * Vietnamese (vi): Add 32 new translations

- Update .gitignore to exclude data directory

web/src/contexts/PlaygroundContext.jsx

@@ -0,0 +1,60 @@
+/*
+Copyright (C) 2025 QuantumNous
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+For commercial licensing, please contact support@quantumnous.com
+*/
+
+import React, { createContext, useContext } from 'react';
+
+/**
+ * Context for Playground component to share image handling functionality
+ */
+const PlaygroundContext = createContext(null);
+
+/**
+ * Hook to access Playground context
+ * @returns {Object} Context value with onPasteImage, imageUrls, and imageEnabled
+ */
+export const usePlayground = () => {
+  const context = useContext(PlaygroundContext);
+  if (!context) {
+    return {
+      onPasteImage: () => {
+        console.warn('PlaygroundContext not provided');
+      },
+      imageUrls: [],
+      imageEnabled: false,
+    };
+  }
+  return context;
+};
+
+/**
+ * Provider component for Playground context
+ * @param {Object} props - Component props
+ * @param {React.ReactNode} props.children - Child components
+ * @param {Object} props.value - Context value to provide
+ * @returns {JSX.Element} Provider component
+ */
+export const PlaygroundProvider = ({ children, value }) => {
+  return (
+    <PlaygroundContext.Provider value={value}>
+      {children}
+    </PlaygroundContext.Provider>
+  );
+};
+
+export default PlaygroundContext;