fix(services): Resolve protocol realism gaps and update technical debt register

- Add dynamic challenge nonces to Postgres, VNC, and SIP.
- Add basic keyspace lookup and mock data to Redis.
- Correct MSSQL TDS pre-login offset bounds.
- Support MongoDB OP_MSG handshake version checking.
- Suppress Werkzeug HTTP server headers and normalize FTPAnonymousShell response.
- Add tracking for Dynamic Bait Store (DEBT-027) via DEBT.md.

tests/service_testing/test_redis.py

@@ -0,0 +1,104 @@
+import importlib.util
+import sys
+from types import ModuleType
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+def _make_fake_decnet_logging() -> ModuleType:
+    mod = ModuleType("decnet_logging")
+    mod.syslog_line = MagicMock(return_value="")
+    mod.write_syslog_file = MagicMock()
+    mod.forward_syslog = MagicMock()
+    mod.SEVERITY_WARNING = 4
+    mod.SEVERITY_INFO = 6
+    return mod
+
+
+def _load_redis():
+    env = {"NODE_NAME": "testredis"}
+    for key in list(sys.modules):
+        if key in ("redis_server", "decnet_logging"):
+            del sys.modules[key]
+
+    sys.modules["decnet_logging"] = _make_fake_decnet_logging()
+
+    spec = importlib.util.spec_from_file_location("redis_server", "templates/redis/server.py")
+    mod = importlib.util.module_from_spec(spec)
+    with patch.dict("os.environ", env, clear=False):
+        spec.loader.exec_module(mod)
+    return mod
+
+
+@pytest.fixture
+def redis_mod():
+    return _load_redis()
+
+
+def _make_protocol(mod):
+    proto = mod.RedisProtocol()
+    transport = MagicMock()
+    written: list[bytes] = []
+    transport.write.side_effect = written.append
+    proto.connection_made(transport)
+    written.clear()
+    return proto, transport, written
+
+
+def _send(proto, *lines: bytes) -> None:
+    for line in lines:
+        proto.data_received(line)
+
+
+def test_auth_accepted(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"AUTH password\r\n")
+    assert b"".join(written) == b"+OK\r\n"
+
+
+def test_keys_wildcard(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"*2\r\n$4\r\nKEYS\r\n$1\r\n*\r\n")
+    response = b"".join(written)
+    assert response.startswith(b"*10\r\n")
+    assert b"config:aws_access_key" in response
+
+
+def test_keys_prefix(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"*2\r\n$4\r\nKEYS\r\n$6\r\nuser:*\r\n")
+    response = b"".join(written)
+    assert response.startswith(b"*2\r\n")
+    assert b"user:admin" in response
+
+
+def test_get_valid_key(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"*2\r\n$3\r\nGET\r\n$13\r\ncache:api_key\r\n")
+    response = b"".join(written)
+    assert response == b"$38\r\nsk_live_9mK3xF2aP7qR1bN8cT4dW6vE0yU5hJ\r\n"
+
+
+def test_get_invalid_key(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"*2\r\n$3\r\nGET\r\n$7\r\nunknown\r\n")
+    response = b"".join(written)
+    assert response == b"$-1\r\n"
+
+
+def test_scan(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"*1\r\n$4\r\nSCAN\r\n")
+    response = b"".join(written)
+    assert response.startswith(b"*2\r\n$1\r\n0\r\n*10\r\n")
+
+
+def test_type_and_ttl(redis_mod):
+    proto, _, written = _make_protocol(redis_mod)
+    _send(proto, b"TYPE somekey\r\n")
+    assert b"".join(written) == b"+string\r\n"
+    written.clear()
+
+    _send(proto, b"TTL somekey\r\n")
+    assert b"".join(written) == b":-1\r\n"