Fetches account balances from Fava/Beancount

Refactors account balance retrieval to fetch data from Fava/Beancount
for improved accounting accuracy.

Updates user balance retrieval to use Fava/Beancount data source.

Updates Castle settings ledger slug name.

views_api.py

@@ -235,9 +235,23 @@ async def api_get_account(account_id: str) -> Account:
 
 @castle_api_router.get("/api/v1/accounts/{account_id}/balance")
 async def api_get_account_balance(account_id: str) -> dict:
-    """Get account balance"""
-    balance = await get_account_balance(account_id)
-    return {"account_id": account_id, "balance": balance}
+    """Get account balance from Fava/Beancount"""
+    from .fava_client import get_fava_client
+
+    # Get account to retrieve its name
+    account = await get_account(account_id)
+    if not account:
+        raise HTTPException(status_code=404, detail="Account not found")
+
+    # Query Fava for balance
+    fava = get_fava_client()
+    balance_data = await fava.get_account_balance(account.name)
+
+    return {
+        "account_id": account_id,
+        "balance": balance_data["sats"],  # Balance in satoshis
+        "positions": balance_data["positions"]  # Full Beancount positions with cost basis
+    }
 
 
 @castle_api_router.get("/api/v1/accounts/{account_id}/transactions")
@@ -683,25 +697,28 @@ async def api_create_revenue_entry(
 async def api_get_my_balance(
     wallet: WalletTypeInfo = Depends(require_invoice_key),
 ) -> UserBalance:
-    """Get current user's balance with the Castle"""
+    """Get current user's balance with the Castle (from Fava/Beancount)"""
     from lnbits.settings import settings as lnbits_settings
+    from .fava_client import get_fava_client
+
+    fava = get_fava_client()
 
     # If super user, show total castle position
     if wallet.wallet.user == lnbits_settings.super_user:
-        all_balances = await get_all_user_balances()
+        all_balances = await fava.get_all_user_balances()
 
         # Calculate total:
         # Positive balances = Castle owes users (liabilities)
         # Negative balances = Users owe Castle (receivables)
         # Net: positive means castle owes, negative means castle is owed
-        total_liabilities = sum(b.balance for b in all_balances if b.balance > 0)
-        total_receivables = sum(abs(b.balance) for b in all_balances if b.balance < 0)
+        total_liabilities = sum(b["balance"] for b in all_balances if b["balance"] > 0)
+        total_receivables = sum(abs(b["balance"]) for b in all_balances if b["balance"] < 0)
         net_balance = total_liabilities - total_receivables
 
         # Aggregate fiat balances from all users
         total_fiat_balances = {}
         for user_balance in all_balances:
-            for currency, amount in user_balance.fiat_balances.items():
+            for currency, amount in user_balance["fiat_balances"].items():
                 if currency not in total_fiat_balances:
                     total_fiat_balances[currency] = Decimal("0")
                 # Add all balances (positive and negative)
@@ -715,37 +732,56 @@ async def api_get_my_balance(
             fiat_balances=total_fiat_balances,
         )
 
-    # For regular users, show their individual balance
-    return await get_user_balance(wallet.wallet.user)
+    # For regular users, show their individual balance from Fava
+    balance_data = await fava.get_user_balance(wallet.wallet.user)
+
+    return UserBalance(
+        user_id=wallet.wallet.user,
+        balance=balance_data["balance"],
+        accounts=[],  # Could populate from balance_data["accounts"] if needed
+        fiat_balances=balance_data["fiat_balances"],
+    )
 
 
 @castle_api_router.get("/api/v1/balance/{user_id}")
 async def api_get_user_balance(user_id: str) -> UserBalance:
-    """Get a specific user's balance with the Castle"""
-    return await get_user_balance(user_id)
+    """Get a specific user's balance with the Castle (from Fava/Beancount)"""
+    from .fava_client import get_fava_client
+
+    fava = get_fava_client()
+    balance_data = await fava.get_user_balance(user_id)
+
+    return UserBalance(
+        user_id=user_id,
+        balance=balance_data["balance"],
+        accounts=[],
+        fiat_balances=balance_data["fiat_balances"],
+    )
 
 
 @castle_api_router.get("/api/v1/balances/all")
 async def api_get_all_balances(
     wallet: WalletTypeInfo = Depends(require_admin_key),
 ) -> list[dict]:
-    """Get all user balances (admin/super user only)"""
+    """Get all user balances (admin/super user only) from Fava/Beancount"""
     from lnbits.core.crud.users import get_user
+    from .fava_client import get_fava_client
 
-    balances = await get_all_user_balances()
+    fava = get_fava_client()
+    balances = await fava.get_all_user_balances()
 
     # Enrich with username information
     result = []
     for balance in balances:
-        user = await get_user(balance.user_id)
-        username = user.username if user and user.username else balance.user_id[:16] + "..."
+        user = await get_user(balance["user_id"])
+        username = user.username if user and user.username else balance["user_id"][:16] + "..."
 
         result.append({
-            "user_id": balance.user_id,
+            "user_id": balance["user_id"],
             "username": username,
-            "balance": balance.balance,
-            "fiat_balances": balance.fiat_balances,
-            "accounts": [acc.dict() for acc in balance.accounts],
+            "balance": balance["balance"],
+            "fiat_balances": balance["fiat_balances"],
+            "accounts": balance["accounts"],
         })
 
     return result