Bug: Route not found and usability improvement

[Wgil]

Thanks for maintaining polar, I find it really helpful to understand how Lightning works behind the scenes. I wanted to give some feedback which i'm unsure if are bugs or expected.

1. For some reason I can't figure out, after creating a channel between alice (LND) and carol (Eclair), carol cannot pay alice's invoices and I'm getting route not found.

To Reproduce

• Create a network with default settings.
• Create a channel between alice and carol. I also tried creating another channel from carol to alice but the issue is still there.
• Send some sats to carol if balance is empty.
• Try to create an invoice from alice and pay it from carol.

2. Another usability improvement that I found is that the app lets me pay invoices from nodes with 0 sats, Bob in this case. It should probably stop me from doing it and suggest to add some sats first.

Desktop (please complete the following information):

• OS: [e.g. OSX Mojave or Windows 10 v1903]
• Polar Version: v4.0.0
• Docker Version: v28.5.1
• Docker Compose Version: Compose v2.40.3-desktop.1

I can work on these if helpful.
Thanks