Wallet limits: max balance, daily max withdraw, transactions per sec (#2223)

Co-authored-by: benarc <ben@arc.wales>
Co-authored-by: Pavol Rusnak <pavol@rusnak.io>
Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

lnbits/settings.py

@@ -116,6 +116,9 @@ class SecuritySettings(LNbitsSettings):
     lnbits_notifications: bool = Field(default=False)
     lnbits_killswitch: bool = Field(default=False)
     lnbits_killswitch_interval: int = Field(default=60)
+    lnbits_wallet_limit_max_balance: int = Field(default=0)
+    lnbits_wallet_limit_daily_max_withdraw: int = Field(default=0)
+    lnbits_wallet_limit_secs_between_trans: int = Field(default=0)
     lnbits_watchdog: bool = Field(default=False)
     lnbits_watchdog_interval: int = Field(default=60)
     lnbits_watchdog_delta: int = Field(default=1_000_000)
@@ -125,6 +128,13 @@ class SecuritySettings(LNbitsSettings):
         )
     )
 
+    def is_wallet_max_balance_exceeded(self, amount):
+        return (
+            self.lnbits_wallet_limit_max_balance
+            and self.lnbits_wallet_limit_max_balance > 0
+            and amount > self.lnbits_wallet_limit_max_balance
+        )
+
 
 class FakeWalletFundingSource(LNbitsSettings):
     fake_wallet_secret: str = Field(default="ToTheMoon1")