Fix: copy button was storing literal template string

HEEX doesn't interpolate {} inside quoted attribute values.
Use data-token attribute + .dataset.token instead.

lib/pinchflat_web/controllers/settings/setting_html/setting_form.html.heex

@@ -38,10 +38,11 @@
 
     <div class="mt-4" x-data="{ revealed: false, copied: false }">
       <%= if Settings.get!(:api_token) do %>
+        <% token = Settings.get!(:api_token) %>
         <div class="flex items-center gap-3 flex-wrap">
           <code class="font-mono text-sm bg-meta-2 dark:bg-meta-4 px-3 py-2 rounded break-all">
-            <span x-show="!revealed">{String.slice(Settings.get!(:api_token), 0, 12)}••••••••</span>
-            <span x-show="revealed" x-cloak>{Settings.get!(:api_token)}</span>
+            <span x-show="!revealed">{String.slice(token, 0, 12)}••••••••</span>
+            <span x-show="revealed" x-cloak>{token}</span>
           </code>
           <button type="button" class="text-sm underline" @click="revealed = !revealed">
             <span x-show="!revealed">Show</span>
@@ -50,7 +51,8 @@
           <button
             type="button"
             class="text-sm underline"
-            @click="navigator.clipboard.writeText('{Settings.get!(:api_token)}').then(() => { copied = true; setTimeout(() => copied = false, 2000) })"
+            data-token={token}
+            @click="navigator.clipboard.writeText($el.dataset.token).then(() => { copied = true; setTimeout(() => copied = false, 2000) })"
           >
             <span x-show="!copied">Copy</span>
             <span x-show="copied" x-cloak>Copied!</span>