Add line wrap toggle for editor and paste viewer (#130)

Shared client-side preference in localStorage 'palette-wrap', default
off. Toggle button on /new editor head and paste title bar, plus a Line
wrap checkbox in the settings menu; all read/write the same preference.
Active state uses the accent treatment like other toggles. No em dashes
in UI text.

internal/web/templates/layout.html

@@ -46,6 +46,37 @@
   // do not persist anything here: URL theme is a one-off override
   document.documentElement.dataset.preset = dark ? PAIRS[t].dark : PAIRS[t].light;
 })();
+// #130: shared line wrap preference (localStorage 'palette-wrap', default off)
+(function () {
+  function wrapOn() {
+    try { return localStorage.getItem('palette-wrap') === '1'; } catch (e) { return false; }
+  }
+  function wrapApply(on) {
+    if (on) document.documentElement.setAttribute('data-wrap', '1');
+    else document.documentElement.removeAttribute('data-wrap');
+    document.querySelectorAll('.wrap-toggle').forEach(function (b) {
+      b.setAttribute('aria-pressed', on ? 'true' : 'false');
+    });
+    var s = document.getElementById('wrap-setting');
+    if (s) s.checked = on;
+  }
+  window.paletteWrapToggle = function () {
+    var on = !wrapOn();
+    try { localStorage.setItem('palette-wrap', on ? '1' : '0'); } catch (e) {}
+    wrapApply(on);
+    return on;
+  };
+  document.addEventListener('DOMContentLoaded', function () {
+    wrapApply(wrapOn());
+    document.querySelectorAll('.wrap-toggle').forEach(function (b) {
+      b.addEventListener('click', function () { window.paletteWrapToggle(); });
+    });
+    var s = document.getElementById('wrap-setting');
+    if (s) s.addEventListener('change', function () {
+      if (s.checked !== wrapOn()) window.paletteWrapToggle();
+    });
+  });
+})();
 </script>
 {{end}}
 

internal/web/templates/new.html

@@ -16,6 +16,7 @@
           <option>markdown</option><option>text</option>
         </select>
         <button class="btn btn-icon" id="reguess" title="Re-detect language" type="button"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M21 12a9 9 0 1 1-2.64-6.36"/><polyline points="21 3 21 9 15 9"/></svg></button>
+        <button type="button" class="btn btn-icon wrap-toggle" id="wrap-toggle" title="Toggle line wrap" aria-pressed="false">wrap</button>
       </div>
     </div>
     <div class="float editor-wrap">

internal/web/templates/paste.html

@@ -6,6 +6,7 @@
       <h1>{{if .Title}}{{.Title}}{{else}}Untitled paste{{end}}</h1>
       {{if .CustomSlug}}<span class="slug">/{{.CustomSlug}}</span>{{end}}
       <div class="spacer"></div>
+      <button type="button" class="iconbtn wrap-toggle" title="Toggle line wrap" aria-pressed="false">wrap</button>
       <a class="iconbtn" href="/raw/{{.ID}}">raw</a>
       <a class="iconbtn" href="#" id="copy-btn" onclick="copyContent(this); return false;">copy</a>
       {{if .DeletionToken}}<a class="iconbtn danger" href="#" onclick="redeem('{{.DeletionToken}}'); return false;">delete</a>{{end}}

internal/web/templates/settings.html

@@ -13,6 +13,8 @@
         <svg class="icon-moon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"/></svg>
         <span>Dark mode</span>
       </button>
+      <h3 style="margin-top:18px">Editor</h3>
+      <label class="toggle" for="wrap-setting" style="display:inline-flex"><input type="checkbox" id="wrap-setting"> Line wrap</label>
       <p class="admin-link-row"><a class="admin-link" href="/admin">Admin</a></p>
     </div>
   </div>