feat(gallery+editor): dedicated /gallery page, homepage teaser, in-content images

Homepage gallery:
- Show only 3 before/after samples as a teaser (was: all items)
- Add "مشاهده گالری کامل (N نمونه)" CTA when more than 3 exist
- Remove the now-pointless category tabs from the teaser

New /gallery page:
- Full before/after grid with category filter tabs (deduped from data)
- Responsive cards with قبل/بعد labels + captions, empty state
- Added to sitemap.xml (priority 0.8)

Blog content editor:
- New 🖼 تصویر toolbar button inserts an uploaded image at the cursor
  (direct upload, no forced crop) — for richer post bodies
- Responsive img styling on the public post page

Note: the filler-lab-soorat cover not showing is a data issue — that
post has an empty featuredImage in the DB (verified); re-upload + save
fixes it. The upload/save path itself is correct.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

DrSousan.Api/wwwroot/admin/index.html

@@ -1027,6 +1027,7 @@ tr:hover td{background:#FAFBFC}
             <button onclick="fmt('insertUnorderedList')">• لیست</button>
             <button onclick="fmt('insertOrderedList')">۱. لیست</button>
             <button onclick="insLink()">🔗 لینک</button>
+            <button onclick="insImage()" title="درج تصویر در متن">🖼 تصویر</button>
           </div>
           <div class="editor-content" id="post-content" contenteditable="true" dir="rtl"></div>
         </div>
@@ -2244,6 +2245,31 @@ function checkSeo(){
 function fmt(cmd){document.getElementById('post-content').focus();document.execCommand(cmd);}
 function fmtBlock(tag){document.getElementById('post-content').focus();document.execCommand('formatBlock',false,tag);}
 function insLink(){const url=prompt('آدرس لینک:');if(url){document.getElementById('post-content').focus();document.execCommand('createLink',false,url);}}
+// Insert an image into the post content at the cursor (uploads directly, no forced crop)
+function insImage(){
+  const editor=document.getElementById('post-content');
+  editor.focus();
+  const sel=window.getSelection();
+  const savedRange=sel.rangeCount?sel.getRangeAt(0):null;
+  const fileInput=document.createElement('input');
+  fileInput.type='file';
+  fileInput.accept='image/jpeg,image/png,image/webp,image/gif';
+  fileInput.onchange=async()=>{
+    const file=fileInput.files[0];if(!file)return;
+    toast('در حال آپلود تصویر...');
+    try{
+      const fd=new FormData();fd.append('file',file);
+      const r=await fetch('/api/upload',{method:'POST',headers:{'Authorization':`Bearer ${token}`},body:fd});
+      if(!r.ok)throw new Error(await r.text());
+      const {url}=await r.json();
+      editor.focus();
+      if(savedRange){sel.removeAllRanges();sel.addRange(savedRange);}
+      document.execCommand('insertHTML',false,`<img src="${url}" alt="" style="max-width:100%;height:auto;border-radius:12px;margin:1rem 0;display:block"/><p><br></p>`);
+      toast('تصویر در متن درج شد ✓');
+    }catch(e){toast('خطا در آپلود: '+e.message,'error');}
+  };
+  fileInput.click();
+}
 
 // ── Modal helpers ─────────────────────────────────────────────────────────────
 function closeModal(id){document.getElementById(id).classList.add('hidden');}