Add reasoning effort

internal/service/templates/static/modal/compose-settings.gohtml

@@ -29,6 +29,24 @@
           aria-label="Max iterations"
         />
       </div>
+
+      <div class="settings-field">
+        <label class="settings-label" for="reasoning-budget-input">
+          Reasoning Budget
+          <span class="settings-label__sub">
+            Only supported by some models and inference engines.
+            <br>
+            -1 = unlimited, 0 = off · 512 ≈ low · 2048 ≈ med · 8192 ≈ high
+          </span>
+        </label>
+        <input
+          type="number"
+          class="settings-select"
+          id="reasoning-budget-input"
+          value="-1"
+          aria-label="Reasoning budget"
+        />
+      </div>
     </div>
   </div>
 {{ end }}