feat: Spark L2 (#3715)

Co-authored-by: blackcoffeexbt <87530449+blackcoffeexbt@users.noreply.github.com>
Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

lnbits/settings.py

@@ -606,6 +606,15 @@ class SparkFundingSource(LNbitsSettings):
     spark_token: str | None = Field(default=None)
 
 
+class SparkL2FundingSource(LNbitsSettings):
+    spark_l2_network: str = Field(default="MAINNET")
+    spark_l2_external_endpoint: str | None = Field(default="http://localhost:8765")
+    spark_l2_external_api_key: str | None = Field(default=None)
+    spark_l2_pay_wait_ms: int = Field(default=4000, ge=0)
+    spark_l2_pay_poll_ms: int = Field(default=500, ge=0)
+    spark_l2_stream_keepalive_ms: int = Field(default=15000, ge=0)
+
+
 class LnTipsFundingSource(LNbitsSettings):
     lntips_api_endpoint: str | None = Field(default=None)
     lntips_api_key: str | None = Field(default=None)
@@ -711,6 +720,7 @@ class FundingSourcesSettings(
     PhoenixdFundingSource,
     OpenNodeFundingSource,
     SparkFundingSource,
+    SparkL2FundingSource,
     LnTipsFundingSource,
     NWCFundingSource,
     BreezSdkFundingSource,
@@ -1039,6 +1049,7 @@ class SuperUserSettings(LNbitsSettings):
             "FakeWallet",
             "LNPayWallet",
             "LNbitsWallet",
+            "SparkL2Wallet",
             "LnTipsWallet",
             "LndRestWallet",
             "LndWallet",