fix(packaging): move templates/ into decnet/ package so they ship with pip install

The docker build contexts and syslog_bridge.py lived at repo root, which
meant setuptools (include = ["decnet*"]) never shipped them. Agents
installed via `pip install $RELEASE_DIR` got site-packages/decnet/** but no
templates/, so every deploy blew up in deployer._sync_logging_helper with
FileNotFoundError on templates/syslog_bridge.py.

Move templates/ -> decnet/templates/ and declare it as setuptools
package-data. Path resolutions in services/*.py and engine/deployer.py drop
one .parent since templates now lives beside the code. Test fixtures,
bandit exclude path, and coverage omit glob updated to match.

decnet/templates/mssql/server.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+"""
+MSSQL (TDS)server.
+Reads TDS pre-login and login7 packets, extracts username, responds with
+a login failed error. Logs auth attempts as JSON.
+"""
+
+import asyncio
+import os
+import struct
+from syslog_bridge import syslog_line, write_syslog_file, forward_syslog
+
+NODE_NAME = os.environ.get("NODE_NAME", "dbserver")
+SERVICE_NAME   = "mssql"
+LOG_TARGET = os.environ.get("LOG_TARGET", "")
+
+_PRELOGIN_RESP = bytes([
+    0x04, 0x01, 0x00, 0x2f, 0x00, 0x00, 0x01, 0x00,  # TDS header type=4, status=1, len=47
+    # 0. VERSION option
+    0x00, 0x00, 0x1a, 0x00, 0x06,
+    # 1. ENCRYPTION option
+    0x01, 0x00, 0x20, 0x00, 0x01,
+    # 2. INSTOPT
+    0x02, 0x00, 0x21, 0x00, 0x01,
+    # 3. THREADID
+    0x03, 0x00, 0x22, 0x00, 0x04,
+    # 4. MARS
+    0x04, 0x00, 0x26, 0x00, 0x01,
+    # TERMINATOR
+    0xff,
+    # version data: 14.0.2000
+    0x0e, 0x00, 0x07, 0xd0, 0x00, 0x00,
+    # encryption: NOT_SUP
+    0x02,
+    # instopt
+    0x00,
+    # thread id
+    0x00, 0x00, 0x00, 0x00,
+    # mars
+    0x00,
+])
+
+
+
+
+def _log(event_type: str, severity: int = 6, **kwargs) -> None:
+    line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
+    write_syslog_file(line)
+    forward_syslog(line, LOG_TARGET)
+
+
+def _tds_error_packet(message: str) -> bytes:
+    msg_enc = message.encode("utf-16-le")
+    # Token type 0xAA = ERROR, followed by length, error number, state, class, msg_len, msg
+    token = (
+        b"\xaa"
+        + struct.pack("<H", 4 + 1 + 1 + 2 + len(msg_enc) + 1 + 1 + 1 + 1 + 4)
+        + struct.pack("<I", 18456)   # SQL error number: login failed
+        + b"\x01"                    # state
+        + b"\x0e"                    # class
+        + struct.pack("<H", len(message))
+        + msg_enc
+        + b"\x00"                    # server name length
+        + b"\x00"                    # proc name length
+        + struct.pack("<I", 1)       # line number
+    )
+    done = b"\xfd\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    payload = token + done
+    header = struct.pack(">BBHBBBB", 0x04, 0x01, len(payload) + 8, 0x00, 0x00, 0x01, 0x00)
+    return header + payload
+
+
+class MSSQLProtocol(asyncio.Protocol):
+    def __init__(self):
+        self._transport = None
+        self._peer = None
+        self._buf = b""
+        self._prelogin_done = False
+
+    def connection_made(self, transport):
+        self._transport = transport
+        self._peer = transport.get_extra_info("peername", ("?", 0))
+        _log("connect", src=self._peer[0], src_port=self._peer[1])
+
+    def data_received(self, data):
+        self._buf += data
+        while len(self._buf) >= 8:
+            pkt_type = self._buf[0]
+            pkt_len = struct.unpack(">H", self._buf[2:4])[0]
+            if pkt_len < 8:
+                _log("unknown_packet", src=self._peer[0], pkt_type=hex(pkt_type))
+                self._transport.close()
+                self._buf = b""
+                return
+            if len(self._buf) < pkt_len:
+                break
+            payload = self._buf[8:pkt_len]
+            self._buf = self._buf[pkt_len:]
+            self._handle_packet(pkt_type, payload)
+            if self._transport.is_closing():
+                self._buf = b""
+                break
+
+    def _handle_packet(self, pkt_type: int, payload: bytes):
+        if pkt_type == 0x12:  # Pre-login
+            self._transport.write(_PRELOGIN_RESP)
+            self._prelogin_done = True
+        elif pkt_type == 0x10:  # Login7
+            username = self._parse_login7_username(payload)
+            _log("auth", src=self._peer[0], username=username)
+            self._transport.write(_tds_error_packet("Login failed for user."))
+            self._transport.close()
+        else:
+            _log("unknown_packet", src=self._peer[0], pkt_type=hex(pkt_type))
+            self._transport.close()
+
+    def _parse_login7_username(self, payload: bytes) -> str:
+        try:
+            # Login7 layout: fixed header 36 bytes, then offsets
+            # Username offset at bytes 36-37, length at 38-39
+            if len(payload) < 40:
+                return "<short_packet>"
+            offset = struct.unpack("<H", payload[36:38])[0]
+            length = struct.unpack("<H", payload[38:40])[0]
+            username = payload[offset:offset + length * 2].decode("utf-16-le", errors="replace")
+            return username
+        except Exception:
+            return "<parse_error>"
+
+    def connection_lost(self, exc):
+        _log("disconnect", src=self._peer[0] if self._peer else "?")
+
+
+async def main():
+    _log("startup", msg=f"MSSQL server starting as {NODE_NAME}")
+    loop = asyncio.get_running_loop()
+    server = await loop.create_server(MSSQLProtocol, "0.0.0.0", 1433)  # nosec B104
+    async with server:
+        await server.serve_forever()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())