fix(prometheus, syslog): a target or pattern pauses with a Pause/Resume button, not an "on" tick box in its form (#6419)

Monitors, schedules and maintenance plans already pause with a
Pause/Resume button and say "Paused" where they're listed. Prometheus
targets and syslog patterns only had a tick box inside the edit form,
so a target refused by its endpoint couldn't be stopped from its page.

- Both get a Pause/Resume button (target page and list; patterns list)
  posting to /toggle, recorded in the audit log, and a Paused badge.
- The forms lose the tick box. A new one starts running; an edit keeps
  whether it is paused.
- A target's "off" state is now "paused", in its pages and MCP tools.
  A resumed target reads "not scraped yet" until its next scrape, and its
  counter rates start over.

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

plugins/prometheus/mcp_tools.py

@@ -19,7 +19,7 @@ from .models import PrometheusTarget
 from .routes import group_series
 from .service import OWN_METRICS, SOURCE, target_state
 
-REACHES = ("down", "stale", "pending", "up", "off")
+REACHES = ("down", "stale", "pending", "up", "paused")
 _ORDER = {r: i for i, r in enumerate(REACHES)}
 
 
@@ -37,7 +37,7 @@ async def list_prometheus_targets() -> dict:
     """The /metrics endpoints Steward scrapes, not answering first.
 
     `reach`: "down" (the last scrape failed; `says` is why), "stale" (not
-    scraped recently), "pending", "up" or "off". `series_kept` /
+    scraped recently), "pending", "up" or "paused". `series_kept` /
     `series_dropped` count the newest scrape's series the keep/drop patterns
     let through or left out; `series_capped` those past `series_cap`, which
     were not stored. get_prometheus_target lists a target's series;
@@ -94,7 +94,7 @@ async def get_prometheus_target(target: str, search: str = "", limit: int = 100)
 
 
 def target_findings(views: list[dict]) -> list[dict]:
-    """A target whose last scrape failed. Stale and off are the plugin or
+    """A target whose last scrape failed. Stale and paused are the plugin or
     the admin's choice, not the endpoint, so they are left out."""
     return [finding("warning", "prometheus_target_down", v["name"],
                     f"Prometheus target {v['name']} isn't answering: {v['says']}",