Adds user settings for the Castle extension

Adds functionality to configure the Castle extension, including a wallet ID.

This allows administrators to customize the extension's behavior by specifying a dedicated wallet for castle operations.

crud.py

@@ -8,12 +8,14 @@ from lnbits.helpers import urlsafe_short_hash
 from .models import (
     Account,
     AccountType,
+    CastleSettings,
     CreateAccount,
     CreateEntryLine,
     CreateJournalEntry,
     EntryLine,
     JournalEntry,
     UserBalance,
+    UserCastleSettings,
 )
 
 db = Database("ext_castle")
@@ -345,3 +347,33 @@ async def get_account_transactions(
             transactions.append((entry, line))
 
     return transactions
+
+
+# ===== SETTINGS =====
+
+
+async def create_castle_settings(
+    user_id: str, data: CastleSettings
+) -> CastleSettings:
+    settings = UserCastleSettings(**data.dict(), id=user_id)
+    await db.insert("extension_settings", settings)
+    return settings
+
+
+async def get_castle_settings(user_id: str) -> Optional[CastleSettings]:
+    return await db.fetchone(
+        """
+        SELECT * FROM extension_settings
+        WHERE id = :user_id
+        """,
+        {"user_id": user_id},
+        CastleSettings,
+    )
+
+
+async def update_castle_settings(
+    user_id: str, data: CastleSettings
+) -> CastleSettings:
+    settings = UserCastleSettings(**data.dict(), id=user_id)
+    await db.update("extension_settings", settings)
+    return settings