fix(prometheus): a refused token stops the scraping, as Home Assistant bans an address after a few refusals (#6355)

Also names the Home Assistant connection by its address in the audit log and
timeline, where its id showed.

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

plugins/prometheus/routes.py

@@ -153,6 +153,7 @@ async def save_target(target_id: str):
             # Where it is or what is kept may have changed: the last outcome no
             # longer describes it, so the page says "not scraped yet" until the next scrape.
             target.last_scraped_at = target.last_ok_at = target.last_error = None
+            target.refused = False
             target.last_kept = target.last_dropped = target.last_capped = 0
             if old_name != target.name:
                 # Its history is stored under its name, and its labelled series
@@ -188,6 +189,7 @@ async def toggle_target(target_id: str):
                 # Resumed: it reads "not scraped yet" until the next scrape,
                 # rather than stale from before the pause.
                 target.last_scraped_at = target.last_error = None
+                target.refused = False
             enabled, name = target.enabled, target.name
     # A rate needs two readings in a row; one from before the pause isn't one.
     from . import scheduler