fix: take the file edit limit in the panel from the agent's read cap

The limit was repeated in the page; a file of exactly the cap is read
in full, so it is editable too.

internal/server/web/templates/files.html

@@ -107,7 +107,7 @@
     }).then(r => r.json()).catch(e => ({ok:false, error:'ошибка сети'})).finally(() => setBusy(false));
   };
 
-  const EDIT_LIMIT = 5 * 1024 * 1024;
+  const EDIT_LIMIT = {{.EditLimit}};
 
   // Monochrome inline icons (inherit button color via currentColor).
   const SVG = '<svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">';
@@ -190,10 +190,10 @@
       msg.textContent = 'Размер: '+fmtSize(d.size);
     } else {
       ta.value = new TextDecoder().decode(b64ToBytes(d.content));
-      const editable = d.size < EDIT_LIMIT && !d.truncated;
+      const editable = d.size <= EDIT_LIMIT && !d.truncated;
       ta.readOnly = !editable;
       save.style.display = editable ? '' : 'none';
-      msg.textContent = 'Размер: '+fmtSize(d.size) + (d.truncated?' · показано первые 5 МБ':'') + (editable?' · редактируемо':' · только чтение (≥ 5 МБ)');
+      msg.textContent = 'Размер: '+fmtSize(d.size) + (d.truncated?' · показано первые '+fmtSize(EDIT_LIMIT):'') + (editable?' · редактируемо':' · только чтение (больше '+fmtSize(EDIT_LIMIT)+')');
       save.onclick = async () => {
         const bytes = new TextEncoder().encode(ta.value);
         const w = await api('write', {path: join(cwd, e.name), data: bytesToB64(bytes)});