feat: add default pay link creation for users with username in user account setup

lnbits/core/services/users.py

@@ -86,6 +86,14 @@ async def create_user_account_no_ckeck(
             except Exception as e:
                 logger.error(f"Error enabeling default extension {ext_id}: {e}")
 
+        # Create default pay link for users with username
+        if account.username and "lnurlp" in user_extensions:
+            try:
+                await _create_default_pay_link(account, wallet) # TODO: determine if this should pass `conn=conn`?
+                logger.info(f"Created default pay link for user {account.username}")
+            except Exception as e:
+                logger.error(f"Failed to create default pay link for user {account.username}: {e}")
+
         user = await get_user_from_account(account, conn=conn)
     if not user:
         raise ValueError("Cannot find user for account.")
@@ -192,3 +200,54 @@ async def init_admin_settings(super_user: str | None = None) -> SuperSettings:
 
     editable_settings = EditableSettings.from_dict(settings.dict())
     return await create_admin_settings(account.id, editable_settings.dict())
+
+
+async def _create_default_pay_link(account: Account, wallet) -> None:
+    """Create a default pay link for new users with username (Bitcoinmat receiving address)"""
+    try:
+        # Try dynamic import that works with extensions in different locations
+        import importlib
+        import sys
+
+        # First try the standard import path
+        try:
+            lnurlp_crud = importlib.import_module("lnbits.extensions.lnurlp.crud")
+            lnurlp_models = importlib.import_module("lnbits.extensions.lnurlp.models")
+        except ImportError:
+            # If that fails, try importing from external extensions path
+            # This handles cases where extensions are in /var/lib/lnbits/extensions
+            try:
+                # Add extensions path to sys.path if not already there
+                extensions_path = settings.lnbits_extensions_path or "/var/lib/lnbits/extensions"
+                if extensions_path not in sys.path:
+                    sys.path.insert(0, extensions_path)
+
+                lnurlp_crud = importlib.import_module("lnurlp.crud")
+                lnurlp_models = importlib.import_module("lnurlp.models")
+            except ImportError as e:
+                logger.warning(f"lnurlp extension not found in any location: {e}")
+                return
+
+        create_pay_link = lnurlp_crud.create_pay_link
+        CreatePayLinkData = lnurlp_models.CreatePayLinkData
+
+
+        pay_link_data = CreatePayLinkData(
+            description="Bitcoinmat Receiving Address",
+            wallet=wallet.id,
+            # Note default `currency` is satoshis when set as NULL in db
+            min=1,  # minimum 1 sat
+            max=500000,  # maximum 500,000 sats
+            comment_chars=0,
+            username=account.username,  # use the username as lightning address
+            zaps=True,
+            disposable=False,
+        )
+
+        await create_pay_link(pay_link_data)
+
+        logger.info(f"Successfully created default pay link for user {account.username}")
+
+    except Exception as e:
+        logger.error(f"Failed to create default pay link: {e}")
+        # Don't raise - we don't want user creation to fail if pay link creation fails