Use grep -F in dmesg filter to prevent interface name treated as regex

grep {iface} treats dots and other special chars as regex metacharacters.
Switch to grep -F -- {iface} for fixed-string matching and to prevent
a leading dash in the interface name from being parsed as a grep flag.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

diagnose.py

@@ -68,7 +68,7 @@ class DiagnosticsRunner:
             f' echo "=== ip_route ===";'
             f' ip route show dev {q} 2>/dev/null;'
             f' echo "=== dmesg ===";'
-            f' dmesg 2>/dev/null | grep {q} | tail -50;'
+            f' dmesg 2>/dev/null | grep -F -- {q} | tail -50;'
             f' echo "=== lldpctl ===";'
             f' lldpctl 2>/dev/null || echo "lldpd not running";'
             f' echo "=== end ==="'

monitor.py

@@ -734,7 +734,7 @@ class NetworkMonitor:
                             f'Interface {iface} on {host} went link-down ({_now_utc()})',
                         )
                         if not sup and consec >= self.fail_thresh:
-                            self._ticket_interface(event_id, is_new, host, iface, consec)
+                            self._ticket_interface(event_id, host, iface, consec)
 
             if host_has_regression:
                 hosts_with_regression.append(host)
@@ -771,7 +771,7 @@ class NetworkMonitor:
             db.resolve_event('cluster_network_issue', self.cluster_name, '')
 
     def _ticket_interface(
-        self, event_id: int, is_new: bool, host: str, iface: str, consec: int
+        self, event_id: int, host: str, iface: str, consec: int
     ) -> None:
         title = (
             f'[{host}][auto][production][issue][network][single-node] '
@@ -810,11 +810,11 @@ class NetworkMonitor:
                     f'UniFi {name} ({d.get("ip","")}) offline ({_now_utc()})',
                 )
                 if not sup and consec >= self.fail_thresh:
-                    self._ticket_unifi(event_id, is_new, d)
+                    self._ticket_unifi(event_id, d)
             else:
                 db.resolve_event('unifi_device_offline', name, d.get('type', ''))
 
-    def _ticket_unifi(self, event_id: int, is_new: bool, device: dict) -> None:
+    def _ticket_unifi(self, event_id: int, device: dict) -> None:
         name = device['name']
         title = (
             f'[{name}][auto][production][issue][network][single-node] '
@@ -850,12 +850,12 @@ class NetworkMonitor:
                     f'Host {name} ({ip}) unreachable via ping ({_now_utc()})',
                 )
                 if not sup and consec >= self.fail_thresh:
-                    self._ticket_unreachable(event_id, is_new, name, ip, consec)
+                    self._ticket_unreachable(event_id, name, ip, consec)
             else:
                 db.resolve_event('host_unreachable', name, ip)
 
     def _ticket_unreachable(
-        self, event_id: int, is_new: bool, name: str, ip: str, consec: int
+        self, event_id: int, name: str, ip: str, consec: int
     ) -> None:
         title = (
             f'[{name}][auto][production][issue][network][single-node] '