feat: implement unified chat system with NIP-C7 and NIP-29 support

Core Architecture:
- Protocol adapter pattern for chat implementations
- Base adapter interface with protocol-specific implementations
- Auto-detection of protocol from identifier format
- Reactive message loading via EventStore observables

Protocol Implementations:
- NIP-C7 adapter: Simple chat (kind 9) with npub/nprofile support
- NIP-29 adapter: Relay-based groups with member roles and moderation
- Protocol-aware reply message loading with relay hints
- Proper NIP-29 members/admins fetching using #d tags

UI Components:
- ChatViewer: Main chat interface with virtualized message timeline
- ChatMessage: Message rendering with reply preview
- ReplyPreview: Auto-loading replied-to messages from relays
- MembersDropdown: Virtualized member list with role labels
- RelaysDropdown: Connection status for chat relays
- ChatComposer: Message input with send functionality

Command System:
- chat command with identifier parsing and auto-detection
- Support for npub, nprofile, NIP-05, and relay'group-id formats
- Integration with window system and dynamic titles

NIP-29 Specific:
- Fetch kind:39000 (metadata), kind:39001 (admins), kind:39002 (members)
- Extract roles from p tags: ["p", "<pubkey>", "<role1>", "<role2>"]
- Role normalization (admin, moderator, host, member)
- Single group relay connection management

Testing:
- Comprehensive chat parser tests
- Protocol adapter test structure
- All tests passing (704 tests)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/test/setup.ts

@@ -10,3 +10,21 @@ import "fake-indexeddb/auto";
 // Polyfill WebSocket - required by nostr-tools relay code
 import { WebSocket } from "ws";
 globalThis.WebSocket = WebSocket as unknown as typeof globalThis.WebSocket;
+
+// Polyfill localStorage - required by state management and accounts
+const localStorageMock = (() => {
+  let store: Record<string, string> = {};
+  return {
+    getItem: (key: string) => store[key] || null,
+    setItem: (key: string, value: string) => {
+      store[key] = value.toString();
+    },
+    removeItem: (key: string) => {
+      delete store[key];
+    },
+    clear: () => {
+      store = {};
+    },
+  };
+})();
+globalThis.localStorage = localStorageMock as Storage;