Add CAT (TS 102 223) command decoding + fix AUTHENTICATE naming

- CAT_COMMAND_TYPES: complete Type of Command table from TS 102 223 §9.4
- ENVELOPE_TYPES: D1-D7 envelope tags
- parse_tlv(): minimal BER-TLV parser
- decode_cat(): FETCH → proactive command name (via D0→81 type byte);
  ENVELOPE → envelope type name
- AUTHENTICATE (0x88/0x89) unified to 'AUTHENTICATE' (no suffix)
- decoded dict gains 'cat_command' field for FETCH/ENVELOPE
- tests/test_decode.py: 14 new tests (TLV, naming, CAT, tables)

tests/test_decode.py

@@ -0,0 +1,96 @@
+"""Tests for server APDU/CAT decoding."""
+
+import unittest
+
+from simtrace2_pysniff.server.decode import (
+    decode_message,
+    decode_sniff_msg,
+    CAT_COMMAND_TYPES,
+    ENVELOPE_TYPES,
+    parse_tlv,
+)
+
+
+class TestParseTlv(unittest.TestCase):
+    def test_simple(self):
+        data = bytes.fromhex('8103010500')
+        self.assertEqual(parse_tlv(data), [(0x81, 3, bytes.fromhex('010500'))])
+
+    def test_multiple(self):
+        data = bytes.fromhex('810301050082028182')
+        self.assertEqual(parse_tlv(data), [
+            (0x81, 3, bytes.fromhex('010500')),
+            (0x82, 2, bytes.fromhex('8182')),
+        ])
+
+    def test_empty(self):
+        self.assertEqual(parse_tlv(b''), [])
+
+
+class TestAuthenticateNaming(unittest.TestCase):
+    def test_ins_88(self):
+        r = decode_message(bytes.fromhex('0088008122' + '00' * 34 + '6135'))
+        self.assertEqual(r['ins_name'], 'AUTHENTICATE')
+
+    def test_ins_89(self):
+        r = decode_message(bytes.fromhex('0089008122' + '00' * 34 + '6135'))
+        self.assertEqual(r['ins_name'], 'AUTHENTICATE')
+
+
+class TestCatDecoding(unittest.TestCase):
+    def test_fetch_setup_menu(self):
+        r = decode_message(bytes.fromhex(
+            '8012000030D02E810301250082028182050B416C6661204D6F62696C65'
+            '8F16808112089DB0C1C2C0BEB9BAB82F53657474696E67739000'))
+        self.assertEqual(r['ins_name'], 'FETCH')
+        self.assertEqual(r['cat_command'], 'SET UP MENU')
+
+    def test_fetch_setup_event_list(self):
+        r = decode_message(bytes.fromhex(
+            '801200000FD00D810301050082028182990203129000'))
+        self.assertEqual(r['cat_command'], 'SET UP EVENT LIST')
+
+    def test_fetch_poll_interval(self):
+        r = decode_message(bytes.fromhex(
+            '801200000FD00D8103010300820281820402011E9000'))
+        self.assertEqual(r['cat_command'], 'POLL INTERVAL')
+
+    def test_fetch_provide_local_info(self):
+        r = decode_message(bytes.fromhex(
+            '801200000BD0098103012600820281829000'))
+        self.assertEqual(r['cat_command'], 'PROVIDE LOCAL INFORMATION')
+
+    def test_envelope_event_download(self):
+        r = decode_message(bytes.fromhex(
+            '80C200000CD60A190103020282811B01029000'))
+        self.assertEqual(r['ins_name'], 'ENVELOPE')
+        self.assertEqual(r['cat_command'], 'EVENT DOWNLOAD')
+
+    def test_tr_no_cat(self):
+        r = decode_message(bytes.fromhex(
+            '801400000C8103010500020282810301009130'))
+        self.assertEqual(r['ins_name'], 'TERMINAL RESPONSE')
+        self.assertNotIn('cat_command', r)
+
+    def test_select_no_cat(self):
+        r = decode_message(bytes.fromhex('a0a40000023f009000'))
+        self.assertEqual(r['ins_name'], 'SELECT')
+        self.assertNotIn('cat_command', r)
+
+
+class TestCommandTypeTables(unittest.TestCase):
+    def test_known_values(self):
+        self.assertEqual(CAT_COMMAND_TYPES[0x03], 'POLL INTERVAL')
+        self.assertEqual(CAT_COMMAND_TYPES[0x05], 'SET UP EVENT LIST')
+        self.assertEqual(CAT_COMMAND_TYPES[0x25], 'SET UP MENU')
+        self.assertEqual(CAT_COMMAND_TYPES[0x21], 'DISPLAY TEXT')
+        self.assertEqual(CAT_COMMAND_TYPES[0x24], 'SELECT ITEM')
+        self.assertEqual(CAT_COMMAND_TYPES[0x26], 'PROVIDE LOCAL INFORMATION')
+
+    def test_envelope_known_values(self):
+        self.assertEqual(ENVELOPE_TYPES[0xD3], 'MENU SELECTION')
+        self.assertEqual(ENVELOPE_TYPES[0xD6], 'EVENT DOWNLOAD')
+
+
+if __name__ == '__main__':
+    unittest.main()