Sort subcategories alphabetically with Muut always last

Applied sortSubcategories() to submission form picker, admin category
list, and admin subcategory checkboxes. Added the helper function to
admin.html since it's a standalone file.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin.html

@@ -576,6 +576,15 @@
     // ===========================
     // CATEGORY HELPERS
     // ===========================
+    function sortSubcategories(subs) {
+      return [...subs].sort((a, b) => {
+        const aM = a.fi.toLowerCase() === 'muut' ? 1 : 0;
+        const bM = b.fi.toLowerCase() === 'muut' ? 1 : 0;
+        if (aM !== bM) return aM - bM;
+        return a.fi.localeCompare(b.fi, 'fi');
+      });
+    }
+
     function getCatLabel(id) {
       const cat = ADMIN.categories.find(c => c.id === id);
       return cat ? cat.fi : id;
@@ -589,7 +598,7 @@
       const el   = document.getElementById('catList');
       if (!cats.length) { el.innerHTML = `<p class="empty-state">${at('cat_empty')}</p>`; return; }
       el.innerHTML = cats.map(c => {
-        const subs = (c.subcategories || []).map(s =>
+        const subs = sortSubcategories(c.subcategories || []).map(s =>
           `<span class="subcat-tag">${s.fi} <button onclick="removeSubcat('${c.id}','${s.id}')" class="subcat-remove">✕</button></span>`
         ).join('');
         return `
@@ -670,7 +679,7 @@
     function updateAdminSubcategories(checked = []) {
       const catId = document.getElementById('postCategory').value;
       const cat   = ADMIN.categories.find(c => c.id === catId);
-      const subs  = cat?.subcategories || [];
+      const subs  = sortSubcategories(cat?.subcategories || []);
       const group = document.getElementById('adminSubcatGroup');
       const box   = document.getElementById('adminSubcatCheckboxes');
       if (!subs.length) { group.style.display = 'none'; box.innerHTML = ''; return; }