feat(syslog): a source's lines to read and search, on its page, its host's and its SNMP device's, and over MCP (#6000)

- /plugins/syslog/sources/<id>: the lines newest first, loading as you
  scroll, filtered by severity and worse, app, text and time, with day
  dividers and times to the second in the reader's zone.
- The Syslog page links each source and shows its lines in the last hour.
- A Syslog panel on a host's page and an SNMP device's: the newest lines of
  the sources bound to it or at its address.
- MCP: list_syslog_sources and search_syslog (source, host, text, severity
  and worse, app, range, paging by next_before).
- Shared: escape_like moves to steward/core/like.py and cut_middle to the
  MCP shaping module, replacing four inline copies; |when takes seconds=.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/snmp/routes.py

@@ -50,6 +50,7 @@ def view(device: SnmpDevice, values: dict, now: datetime) -> dict:
     state = device_state(device, _poll_seconds(), now)
     names = {r.key: r.name for r in readings_for(device)}
     return {"id": device.id, "name": device.name, "address": device.address, "port": device.port,
+            "host_id": device.host_id,
             "version": device.version, "reach": state.reach, "says": state.says,
             "polled_at": device.last_polled_at, "ok_at": device.last_ok_at,
             "readings": shown_readings(device, values),

plugins/snmp/templates/snmp/device.html

@@ -40,6 +40,11 @@
 <div class="card field-hint">This device has no readings chosen{% if session.user_role == 'admin' %}; <a href="/plugins/snmp/devices/{{ device.id }}/edit">Edit</a> to choose some{% endif %}.</div>
 {% endif %}
 
+{# The device's own log, when it sends syslog to an added source (#6000). #}
+{% if "syslog" in enabled_plugins %}
+<div hx-get="/plugins/syslog/panel?address={{ device.address|urlencode }}{% if device.host_id %}&amp;host_id={{ device.host_id }}{% endif %}" hx-trigger="load" hx-swap="innerHTML"></div>
+{% endif %}
+
 <script>
 (function () {
   var charts = {{ charts_json | safe }};