feat: implement doctor schedule module, add detail fields to doctor profile, and integrate new appointment API client

appointment/Application.java

@@ -0,0 +1,28 @@
+package vn.sis.appointment;
+
+public final class Application {
+    private Application() {
+    }
+
+    public static void main(String[] args) throws Exception {
+        int port = resolvePort();
+        AppointmentWebServer server = new AppointmentWebServer(port);
+        server.start();
+
+        System.out.printf("S.I.S Appointment Java Web dang chay tai http://localhost:%d%n", port);
+        System.out.println("Nhan Ctrl+C de dung ung dung.");
+    }
+
+    private static int resolvePort() {
+        String value = System.getenv().getOrDefault("PORT", "8080").trim();
+        try {
+            int port = Integer.parseInt(value);
+            if (port < 1 || port > 65535) {
+                throw new IllegalArgumentException("PORT phai nam trong khoang 1-65535.");
+            }
+            return port;
+        } catch (NumberFormatException ex) {
+            throw new IllegalArgumentException("Bien moi truong PORT khong hop le: " + value, ex);
+        }
+    }
+}