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

appointment/Hashes.java

@@ -0,0 +1,21 @@
+package vn.sis.appointment;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.HexFormat;
+
+final class Hashes {
+    private Hashes() {
+    }
+
+    static String sha256(String value) {
+        try {
+            byte[] digest = MessageDigest.getInstance("SHA-256")
+                    .digest(value.getBytes(StandardCharsets.UTF_8));
+            return HexFormat.of().formatHex(digest);
+        } catch (NoSuchAlgorithmException ex) {
+            throw new IllegalStateException("JDK khong ho tro SHA-256.", ex);
+        }
+    }
+}