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>

steward/core/metric_series.py

@@ -10,6 +10,7 @@ from datetime import datetime, timedelta, timezone
 
 from sqlalchemy import func, or_, select, text
 
+from steward.core.like import escape_like
 from steward.core.time_range import bucket_seconds
 from steward.models.metrics import PluginMetric, PluginMetricHourly, PluginMetricLatest
 
@@ -51,7 +52,7 @@ async def resources(db, source_module: str) -> list[str]:
 def _resource_match(resource: str, include_children: bool):
     match = PluginMetricLatest.resource_name == resource
     if include_children:
-        like = resource.replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_") + ":%"
+        like = escape_like(resource) + ":%"
         match = or_(match, PluginMetricLatest.resource_name.like(like, escape="\\"))
     return match