refactor: strip DECNET tokens from container-visible surface

Rename the container-side logging module decnet_logging → syslog_bridge
(canonical at templates/syslog_bridge.py, synced into each template by
the deployer). Drop the stale per-template copies; setuptools find was
picking them up anyway. Swap useradd/USER/chown "decnet" for "logrelay"
so no obvious token appears in the rendered container image.

Apply the same cloaking pattern to the telnet template that SSH got:
syslog pipe moves to /run/systemd/journal/syslog-relay and the relay
is cat'd via exec -a "systemd-journal-fwd". rsyslog.d conf rename
99-decnet.conf → 50-journal-forward.conf. SSH capture script:
/var/decnet/captured → /var/lib/systemd/coredump (real systemd path),
logger tag decnet-capture → systemd-journal. Compose volume updated
to match the new in-container quarantine path.

SD element ID shifts decnet@55555 → relay@55555; synced across
collector, parser, sniffer, prober, formatter, tests, and docs so the
host-side pipeline still matches what containers emit.

templates/telnet/Dockerfile

@@ -10,11 +10,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 # rsyslog: forward auth.* and user.* to named pipe in RFC 5424 format
 RUN printf '%s\n' \
-    '# DECNET log bridge — auth + user events → named pipe as RFC 5424' \
+    '# syslog-relay log bridge — auth + user events → named pipe as RFC 5424' \
     '$template RFC5424fmt,"<%PRI%>1 %TIMESTAMP:::date-rfc3339% %HOSTNAME% %APP-NAME% %PROCID% %MSGID% %STRUCTURED-DATA% %msg%\n"' \
-    'auth,authpriv.*  |/var/run/decnet-logs;RFC5424fmt' \
-    'user.*           |/var/run/decnet-logs;RFC5424fmt' \
-    > /etc/rsyslog.d/99-decnet.conf
+    'auth,authpriv.*  |/run/systemd/journal/syslog-relay;RFC5424fmt' \
+    'user.*           |/run/systemd/journal/syslog-relay;RFC5424fmt' \
+    > /etc/rsyslog.d/50-journal-forward.conf
 
 # Disable imklog — containers can't read /proc/kmsg
 RUN sed -i 's/^\(module(load="imklog"\)/# \1/' /etc/rsyslog.conf

templates/telnet/decnet_logging.py

@@ -1,89 +0,0 @@
-#!/usr/bin/env python3
-"""
-Shared RFC 5424 syslog helper for DECNET service templates.
-
-Services call syslog_line() to format an RFC 5424 message, then
-write_syslog_file() to emit it to stdout — Docker captures it, and the
-host-side collector streams it into the log file.
-
-RFC 5424 structure:
-  <PRI>1 TIMESTAMP HOSTNAME APP-NAME PROCID MSGID [SD-ELEMENT] MSG
-
-Facility: local0 (16), PEN for SD element ID: decnet@55555
-"""
-
-from datetime import datetime, timezone
-from typing import Any
-
-# ─── Constants ────────────────────────────────────────────────────────────────
-
-_FACILITY_LOCAL0 = 16
-_SD_ID = "decnet@55555"
-_NILVALUE = "-"
-
-SEVERITY_EMERG   = 0
-SEVERITY_ALERT   = 1
-SEVERITY_CRIT    = 2
-SEVERITY_ERROR   = 3
-SEVERITY_WARNING = 4
-SEVERITY_NOTICE  = 5
-SEVERITY_INFO    = 6
-SEVERITY_DEBUG   = 7
-
-_MAX_HOSTNAME = 255
-_MAX_APPNAME  = 48
-_MAX_MSGID    = 32
-
-# ─── Formatter ────────────────────────────────────────────────────────────────
-
-def _sd_escape(value: str) -> str:
-    """Escape SD-PARAM-VALUE per RFC 5424 §6.3.3."""
-    return value.replace("\\", "\\\\").replace('"', '\\"').replace("]", "\\]")
-
-
-def _sd_element(fields: dict[str, Any]) -> str:
-    if not fields:
-        return _NILVALUE
-    params = " ".join(f'{k}="{_sd_escape(str(v))}"' for k, v in fields.items())
-    return f"[{_SD_ID} {params}]"
-
-
-def syslog_line(
-    service: str,
-    hostname: str,
-    event_type: str,
-    severity: int = SEVERITY_INFO,
-    timestamp: datetime | None = None,
-    msg: str | None = None,
-    **fields: Any,
-) -> str:
-    """
-    Return a single RFC 5424-compliant syslog line (no trailing newline).
-
-    Args:
-        service:    APP-NAME (e.g. "http", "mysql")
-        hostname:   HOSTNAME (decky node name)
-        event_type: MSGID    (e.g. "request", "login_attempt")
-        severity:   Syslog severity integer (default: INFO=6)
-        timestamp:  UTC datetime; defaults to now
-        msg:        Optional free-text MSG
-        **fields:   Encoded as structured data params
-    """
-    pri     = f"<{_FACILITY_LOCAL0 * 8 + severity}>"
-    ts      = (timestamp or datetime.now(timezone.utc)).isoformat()
-    host    = (hostname or _NILVALUE)[:_MAX_HOSTNAME]
-    appname = (service  or _NILVALUE)[:_MAX_APPNAME]
-    msgid   = (event_type or _NILVALUE)[:_MAX_MSGID]
-    sd      = _sd_element(fields)
-    message = f" {msg}" if msg else ""
-    return f"{pri}1 {ts} {host} {appname} {_NILVALUE} {msgid} {sd}{message}"
-
-
-def write_syslog_file(line: str) -> None:
-    """Emit a syslog line to stdout for Docker log capture."""
-    print(line, flush=True)
-
-
-def forward_syslog(line: str, log_target: str) -> None:
-    """No-op stub. TCP forwarding is now handled by rsyslog, not by service containers."""
-    pass

templates/telnet/entrypoint.sh

@@ -27,12 +27,14 @@ cat /root/.env
 HIST
 fi
 
-# Logging pipeline: named pipe → rsyslogd (RFC 5424) → stdout
-rm -f /var/run/decnet-logs
-mkfifo /var/run/decnet-logs
+# Logging pipeline: named pipe → rsyslogd (RFC 5424) → stdout.
+# Cloak the pipe path and the relay `cat` so `ps aux` / `ls /run` don't
+# betray the honeypot — see ssh/entrypoint.sh for the same pattern.
+mkdir -p /run/systemd/journal
+rm -f /run/systemd/journal/syslog-relay
+mkfifo /run/systemd/journal/syslog-relay
 
-# Relay pipe to stdout so Docker captures all syslog events
-cat /var/run/decnet-logs &
+bash -c 'exec -a "systemd-journal-fwd" cat /run/systemd/journal/syslog-relay' &
 
 # Start rsyslog
 rsyslogd