Adds per-user wallet configuration

Allows users to configure their own wallet ID, enabling
the system to track expenses and receivables on a per-user basis.

Introduces new database table, models, API endpoints, and UI elements
to manage user-specific wallet settings.

views_api.py

@@ -36,8 +36,9 @@ from .models import (
     ReceivableEntry,
     RevenueEntry,
     UserBalance,
+    UserWalletSettings,
 )
-from .services import get_settings, update_settings
+from .services import get_settings, get_user_wallet, update_settings, update_user_wallet
 
 castle_api_router = APIRouter()
 
@@ -56,6 +57,17 @@ async def check_castle_wallet_configured() -> str:
     return settings.castle_wallet_id
 
 
+async def check_user_wallet_configured(user_id: str) -> str:
+    """Ensure user has configured their wallet, return wallet_id"""
+    settings = await get_user_wallet(user_id)
+    if not settings or not settings.user_wallet_id:
+        raise HTTPException(
+            status_code=HTTPStatus.BAD_REQUEST,
+            detail="You must configure your wallet in settings before using this feature.",
+        )
+    return settings.user_wallet_id
+
+
 # ===== UTILITY ENDPOINTS =====
 
 
@@ -170,6 +182,11 @@ async def api_create_expense_entry(
 
     If currency is provided, amount is converted from fiat to satoshis.
     """
+    # Check that castle wallet is configured
+    await check_castle_wallet_configured()
+
+    # Check that user has configured their wallet
+    await check_user_wallet_configured(wallet.wallet.user)
     # Handle currency conversion
     amount_sats = int(data.amount)
     metadata = {}
@@ -502,3 +519,32 @@ async def api_update_settings(
         )
     user_id = "admin"
     return await update_settings(user_id, data)
+
+
+# ===== USER WALLET ENDPOINTS =====
+
+
+@castle_api_router.get("/api/v1/user/wallet")
+async def api_get_user_wallet(
+    user: User = Depends(check_user_exists),
+) -> UserWalletSettings:
+    """Get current user's wallet settings"""
+    settings = await get_user_wallet(user.id)
+    # Return empty settings if not configured (so UI can show setup screen)
+    if not settings:
+        return UserWalletSettings()
+    return settings
+
+
+@castle_api_router.put("/api/v1/user/wallet")
+async def api_update_user_wallet(
+    data: UserWalletSettings,
+    user: User = Depends(check_user_exists),
+) -> UserWalletSettings:
+    """Update current user's wallet settings"""
+    if not data.user_wallet_id:
+        raise HTTPException(
+            status_code=HTTPStatus.BAD_REQUEST,
+            detail="User wallet ID is required",
+        )
+    return await update_user_wallet(user.id, data)