multi: add flap count and last flap time to listpeers

lnrpc/rpc.proto

@@ -1415,6 +1415,20 @@ message Peer {
     spamming us with errors at no cost.
     */
     repeated TimestampedError errors = 12;
+
+    /*
+    The number of times we have recorded this peer going offline or coming
+    online, recorded across restarts. Note that this value is decreased over
+    time if the peer has not recently flapped, so that we can forgive peers
+    with historically high flap counts.
+    */
+    int32 flap_count = 13;
+
+    /*
+    The timestamp of the last flap we observed for this peer. If this value is
+    zero, we have not observed any flaps for this peer.
+    */
+    int64 last_flap_ns = 14;
 }
 
 message TimestampedError {

lnrpc/rpc.swagger.json

@@ -4800,6 +4800,16 @@
             "$ref": "#/definitions/lnrpcTimestampedError"
           },
           "description": "The latest errors received from our peer with timestamps, limited to the 10\nmost recent errors. These errors are tracked across peer connections, but\nare not persisted across lnd restarts. Note that these errors are only\nstored for peers that we have channels open with, to prevent peers from\nspamming us with errors at no cost."
+        },
+        "flap_count": {
+          "type": "integer",
+          "format": "int32",
+          "description": "The number of times we have recorded this peer going offline or coming\nonline, recorded across restarts. Note that this value is decreased over\ntime if the peer has not recently flapped, so that we can forgive peers\nwith historically high flap counts."
+        },
+        "last_flap_ns": {
+          "type": "string",
+          "format": "int64",
+          "description": "The timestamp of the last flap we observed for this peer. If this value is\nzero, we have not observed any flaps for this peer."
         }
       }
     },