feat: add cJSON and SQLite amalgamation source files under deps/

Add the cJSON library (cJSON.c, cJSON.h) and SQLite amalgamation
(sqlite3.c, sqlite3.h, sqlite3ext.h, shell.c) as vendored dependencies
in the deps/ directory for use by the project build system.

example/websocket_server_demo.wren

@@ -0,0 +1,44 @@
+// retoor <retoor@molodetz.nl>
+
+import "websocket" for WebSocketServer
+
+System.print("=== WebSocket Server Demo ===")
+System.print("Listening on ws://0.0.0.0:8080\n")
+
+var server = WebSocketServer.bind("0.0.0.0", 8080)
+
+while (true) {
+  System.print("Waiting for connection...")
+  var ws = server.accept()
+
+  if (ws == null) {
+    System.print("Failed to accept connection")
+    continue
+  }
+
+  System.print("Client connected")
+
+  while (ws.isOpen) {
+    var msg = ws.receive()
+
+    if (msg == null) {
+      System.print("Connection lost")
+      break
+    }
+
+    if (msg.isClose) {
+      System.print("Client sent close frame (code: %(msg.closeCode))")
+      break
+    }
+
+    if (msg.isText) {
+      System.print("Received text: %(msg.text)")
+      ws.send("Echo: %(msg.text)")
+    } else if (msg.isBinary) {
+      System.print("Received binary: %(msg.bytes.count) bytes")
+      ws.sendBinary(msg.bytes)
+    }
+  }
+
+  System.print("Client disconnected\n")
+}