Add chat page, improve chat API, and remove ChatWidget

Introduces a new chat page with end-to-end encryption, conversation list, and message thread UI. Adds new API endpoints for unread message count and debugging chat keys/messages. Improves chat key validation and reciprocal conversation/message creation for local recipients. Removes the old ChatWidget component. Updates login and chat API logic for better Turnstile and key handling.

src/app/api/chat/unread/route.ts

@@ -0,0 +1,42 @@
+import { NextResponse } from 'next/server';
+import { db, chatConversations, chatMessages } from '@/db';
+import { eq, and, isNull, inArray } from 'drizzle-orm';
+import { getSession } from '@/lib/auth';
+
+export async function GET() {
+  try {
+    const session = await getSession();
+    if (!session?.user) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+    }
+
+    // Get user's conversations
+    const conversations = await db.query.chatConversations.findMany({
+      where: eq(chatConversations.participant1Id, session.user.id),
+    });
+
+    if (conversations.length === 0) {
+      return NextResponse.json({ unreadCount: 0 });
+    }
+
+    // Count unread messages across all conversations
+    const conversationIds = conversations.map(c => c.id);
+    
+    const unreadMessages = await db.query.chatMessages.findMany({
+      where: and(
+        inArray(chatMessages.conversationId, conversationIds),
+        isNull(chatMessages.readAt)
+      ),
+    });
+
+    // Filter out messages sent by the current user
+    const unreadCount = unreadMessages.filter(
+      msg => msg.senderHandle !== session.user.handle
+    ).length;
+
+    return NextResponse.json({ unreadCount });
+  } catch (error) {
+    console.error('Get unread chat count error:', error);
+    return NextResponse.json({ error: 'Failed to get unread count' }, { status: 500 });
+  }
+}