Allowance with LNURL-withdraw advanced links

[motorina0]

Problem

• the user might spend more than it wants on a particular site
• there is no way for the user to set a limit on how much and how often it spends
• the user is prompted to confirm each invoice, even if it trusts the particular site

Solution

• use LNURL-w to configure "allowances" for sites
• if an allowance is configured for a site then the extension "pulls" money from that allowance WITHOUT asking the user
  • only a progress dialog is shown
• if one of the LNURL-w limitations is met (count, min/max values, delay) it shows an error message
  • the user can take action and update the limitations (eg: max withdraw amount)

Configure LNURL-withdraw

• the title of the withdraw link must be the exact name of the domain including the protocol (https://htlc.me)
  • trailing slash is NOK: https://htlc.me/ <-- bad
• 

Pay a BOLT 11 invoice

• click on a bolt11 link or "cut it out" from an image
  • no confirmation required, progress dialog shown
• LNURL-pay not supported at the moment
• 

Check Transactions List

• the memo comes from the client invoice itself
• 

That's it!

See negative cases below

[motorina0]

Limits

• check that the limits set by the user are enforced

Withdraw is spent

• 

Wait X seconds

• 

Amount invoice is too high

• 

Amount invoice is too low

• [ ] lnurl-w min value not taken into consideration, LNbits bug?