Initial release: JMAP Webmail Client

A modern, privacy-focused webmail client built with Next.js and the JMAP protocol.
Designed for Stalwart Mail Server.

Features:
- Full email operations (compose, reply, forward, threading)
- Real-time push notifications
- Dark/light theme support
- Mobile responsive design
- Keyboard shortcuts
- Drag-and-drop organization
- i18n (English/French)
- Security-first (external content blocked, HTML sanitization)

components/error/error-boundary.tsx

@@ -0,0 +1,94 @@
+"use client";
+
+import React, { Component, ReactNode } from "react";
+import { useTranslations } from "next-intl";
+import { debug } from "@/lib/debug";
+
+export interface FallbackProps {
+  error: Error;
+  resetError: () => void;
+  t: (key: string) => string;
+}
+
+interface ErrorBoundaryProps {
+  children: ReactNode;
+  fallback: (props: FallbackProps) => ReactNode;
+  onError?: (error: Error, errorInfo: React.ErrorInfo) => void;
+  onReset?: () => void;
+}
+
+interface ErrorBoundaryState {
+  hasError: boolean;
+  error: Error | null;
+}
+
+/**
+ * Core error boundary class component (React requirement).
+ * Receives translation function as prop from the functional wrapper.
+ */
+class ErrorBoundaryCore extends Component<
+  ErrorBoundaryProps & { t: (key: string) => string },
+  ErrorBoundaryState
+> {
+  state: ErrorBoundaryState = { hasError: false, error: null };
+
+  static getDerivedStateFromError(error: Error): ErrorBoundaryState {
+    return { hasError: true, error };
+  }
+
+  componentDidCatch(error: Error, errorInfo: React.ErrorInfo): void {
+    // Always log errors
+    debug.error("[ErrorBoundary]", error.message, {
+      stack: error.stack,
+      componentStack: errorInfo.componentStack,
+    });
+
+    // Call optional error handler
+    this.props.onError?.(error, errorInfo);
+  }
+
+  resetError = (): void => {
+    this.props.onReset?.();
+    this.setState({ hasError: false, error: null });
+  };
+
+  render(): ReactNode {
+    if (this.state.hasError && this.state.error) {
+      return this.props.fallback({
+        error: this.state.error,
+        resetError: this.resetError,
+        t: this.props.t,
+      });
+    }
+    return this.props.children;
+  }
+}
+
+/**
+ * Functional wrapper that injects translations into the error boundary.
+ * Use this component to wrap any part of your UI that might throw errors.
+ *
+ * @example
+ * <ErrorBoundary fallback={SidebarErrorFallback}>
+ *   <Sidebar />
+ * </ErrorBoundary>
+ */
+export function ErrorBoundary({
+  children,
+  fallback,
+  onError,
+  onReset,
+}: ErrorBoundaryProps) {
+  const t = useTranslations("errors");
+
+  return (
+    <ErrorBoundaryCore
+      fallback={fallback}
+      onError={onError}
+      onReset={onReset}
+      t={t}
+    >
+      {children}
+    </ErrorBoundaryCore>
+  );
+}