fix(audit): 审计按账号 id 归属并记录来源 IP/UA，登录失败与限速入审计和指标，写入失败计数告警

deploy/alerts/felis-prometheusrule.yaml

@@ -144,3 +144,25 @@ spec:
               The audit log names the account (action auth.otp.locked); the owner was
               mailed. Unless they fumbled codes, someone is guessing at it
               (troubleshooting §17).
+        - alert: FelisSignInFailures
+          expr: sum(increase(felis_auth_failures_total[15m])) > 30
+          for: 5m
+          labels:
+            severity: warning
+          annotations:
+            summary: "over 30 refused sign-ins in 15 minutes"
+            description: >-
+              Wrong codes, unknown addresses or bad passkey assertions well above people
+              mistyping: someone is guessing or enumerating. `sum by (door, reason)
+              (increase(felis_auth_failures_total[15m]))` shows where; the audit rows
+              (action auth.<door>.failed) carry each caller's client_ip (troubleshooting §17).
+        - alert: FelisAuditWriteFailing
+          expr: increase(felis_audit_write_failures_total[15m]) > 0
+          labels:
+            severity: warning
+          annotations:
+            summary: "felis-api failed to write audit rows"
+            description: >-
+              The actions went through but their audit rows were lost. The felis-api log
+              names each lost row (`audit: lost ...`); the usual cause is PostgreSQL
+              being unreachable or out of disk.