feat: integrate timezone support for message timestamps in chat and overlay components

client/lib/TimezoneContext.tsx

@@ -0,0 +1,43 @@
+'use client';
+
+import React, { createContext, useContext, useState, useEffect } from 'react';
+import { getBrowserTimezone } from './timezone';
+
+interface TimezoneContextType {
+  timezone: string;
+  setTimezone: (timezone: string) => void;
+}
+
+const TimezoneContext = createContext<TimezoneContextType | undefined>(undefined);
+
+export function TimezoneProvider({ children }: { children: React.ReactNode }) {
+  // Initialize with detected timezone immediately to avoid empty string
+  const [timezone, setTimezone] = useState<string>(() => {
+    try {
+      return getBrowserTimezone();
+    } catch (error) {
+      console.warn('Failed to detect timezone on initialization:', error);
+      return 'UTC';
+    }
+  });
+
+  useEffect(() => {
+    // Re-detect browser timezone on mount (in case it changed)
+    const detectedTimezone = getBrowserTimezone();
+    setTimezone(detectedTimezone);
+  }, []);
+
+  return (
+    <TimezoneContext.Provider value={{ timezone, setTimezone }}>
+      {children}
+    </TimezoneContext.Provider>
+  );
+}
+
+export function useTimezone() {
+  const context = useContext(TimezoneContext);
+  if (context === undefined) {
+    throw new Error('useTimezone must be used within a TimezoneProvider');
+  }
+  return context;
+}