feat(tickets): open, comment and resolve tickets from the UI and MCP; known issues on alerts and anomalies (#6351, #6352)

A ticket records a known problem: title, area, hosts, subject, description,
links to alert rules and anomalies, and a log of comments, edits, resolving
and reopening. Opening, resolving (with the resolution as the note) and
reopening go on the timeline; every step is audited, and the audit rows stay
off the timeline.

An alert or anomaly an open ticket covers (by link, by subject, or a
host-wide ticket on the host itself) shows a Known issue badge, and offers
"Open a ticket" prefilled from its rule or anomaly when none does. Hosts,
monitors and containers get a Known issues card.

MCP: list_tickets, get_ticket (viewer); open_ticket, update_ticket,
comment_ticket, resolve_ticket, reopen_ticket (operator). list_alerts and
list_anomalies carry known_issue; get_overview, get_host, get_monitor and
get_container carry open_tickets. Also update_change and delete_change for
changes recorded by hand (author or admin).

Tickets are left out of backups, like the timeline (2026-10-15 ruling).

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

tests/mcp/test_anomaly_review.py

@@ -154,9 +154,18 @@ def test_a_quick_restart_is_shown_though_it_never_broke_the_minute():
     assert _events.gaps_in(ticks, NOW + timedelta(minutes=2), NOW + timedelta(hours=1), [(restart, 35.0)]) == []
 
 
-def test_the_timeline_tools_are_registered_with_their_roles(app):
+def test_the_timeline_and_ticket_tools_are_registered_with_their_roles(app):
     mcp = app.mcp_server
     for name, role, read_only in (("get_timeline", UserRole.viewer, True),
-                                  ("log_change", UserRole.operator, False)):
+                                  ("log_change", UserRole.operator, False),
+                                  ("update_change", UserRole.operator, False),
+                                  ("delete_change", UserRole.operator, False),
+                                  ("list_tickets", UserRole.viewer, True),
+                                  ("get_ticket", UserRole.viewer, True),
+                                  ("open_ticket", UserRole.operator, False),
+                                  ("update_ticket", UserRole.operator, False),
+                                  ("comment_ticket", UserRole.operator, False),
+                                  ("resolve_ticket", UserRole.operator, False),
+                                  ("reopen_ticket", UserRole.operator, False)):
         assert mcp.tool_roles[name] is role, name
         assert mcp._tool_manager.get_tool(name).annotations.read_only_hint is read_only, name