send: stop the Max buttons from cancelling their own submit, show LNURL action errors

Choosing Max on the LNURL-pay page left the button spinning forever. Two
things combined:

The Max buttons set `loading` from their click handler. Svelte flushes
`disabled={loading}` to the DOM before the browser runs the button's
submit activation, and a disabled button submits nothing. Set loading
from the form's onsubmit instead, the way the Send button always did.

The /ln page never passed `form` into the Lnurlp and Lnurlw components,
so any action failure (pay, max or withdraw) rendered nothing and never
reset the spinner. Pass it through, and reset loading when a result
arrives.

Verified in headless Chrome against the dev stack: the bolt11 Max lands
on the fee view, and the LNURL Max surfaces the server's error and
re-enables the buttons.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/routes/(app)/ln/[lnurl]/+page.svelte b/src/routes/(app)/ln/[lnurl]/+page.svelte
index 386df9d2..0f1b030f 100644
--- a/src/routes/(app)/ln/[lnurl]/+page.svelte
+++ b/src/routes/(app)/ln/[lnurl]/+page.svelte
@@ -1,12 +1,14 @@
 <script>
   import Lnurlp from "$comp/Lnurlp.svelte";
   import Lnurlw from "$comp/Lnurlw.svelte";
-  let { data } = $props();
+  let { data, form } = $props();
   let { tag } = data;
 </script>
 
+<!-- form carries the action result; without it a failed pay/max/withdraw
+     showed nothing and left the button spinning forever -->
 {#if tag === "payRequest"}
-  <Lnurlp {data} />
+  <Lnurlp {data} {form} />
 {:else if tag === "withdrawRequest"}
-  <Lnurlw {data} />
+  <Lnurlw {data} {form} />
 {/if}