Widen the webhook page by half so an entrypoint URL fits on one line (closes #350)

The webhook page's container was capped at max-w-6xl, 72rem (1152
px), which made a typical entrypoint URL wrap even in a 1440-pixel
window. It is now capped at 108rem (1728 px). The width is an inline
style because the committed tailwind.css has no class that wide, and
regenerating it needs the unpinned tool. The other pages, the navbar
and the footer keep 72rem.

The title row now wraps: its three buttons made a phone-width window
scroll sideways.

Model: opus-5-5

templates/source_detail.html

@@ -3,10 +3,13 @@
 {{define "title"}}{{.Webhook.Name}} - Webhooker{{end}}
 
 {{define "content"}}
-<div class="max-w-6xl mx-auto px-6 py-8" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
+<!-- Half again as wide as the other pages (max-w-6xl, 72rem), so an
+     entrypoint URL fits on one line. An inline style, because the
+     committed tailwind.css has no class this wide. -->
+<div class="mx-auto px-6 py-8" style="max-width: 108rem" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
     <div class="mb-6">
         <a href="/hooks" class="text-sm text-primary-600 hover:text-primary-700">&larr; Back to webhooks</a>
-        <div class="flex justify-between items-center mt-2">
+        <div class="flex flex-wrap justify-between items-center gap-2 mt-2">
             <div>
                 <h1 class="text-2xl font-medium text-gray-900">{{.Webhook.Name}}</h1>
                 {{if .Webhook.Description}}