Added top-k filtering to webapp. Minor README adjustments.

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

webapp/static/index.html

@@ -41,6 +41,13 @@
           <input id="gen-temperature" type="number" value="0.9" min="0.1" max="2.0" step="0.1" />
           <span class="field-help">Lower = safer/common; higher = more creative/weird. Use temperature ≤ 2.</span>
         </label>
+        <details class="advanced-opts">
+          <summary>Advanced sampling options</summary>
+          <label>Top-k
+            <input id="gen-top-k" type="number" value="50" min="1" max="500" step="1" />
+            <span class="field-help">Limits sampling to the top-k most likely tokens. Lower = more focused; set to 500 to effectively disable. Default 50.</span>
+          </label>
+        </details>
         <button id="generate-btn">Generate</button>
       </div>
 
@@ -116,6 +123,8 @@
         <dl>
           <dt>Temperature</dt>
           <dd>Sampling randomness. Lower values are more conservative; higher values are more exploratory.</dd>
+          <dt>Top-k</dt>
+          <dd>Restricts each sampling step to the k most likely tokens. Lower values make the model more focused; higher values (up to 500) allow more variety.</dd>
           <dt>Target V-grade</dt>
           <dd>The grade token given to the generator. The generated route is also checked by the grade predictor.</dd>
           <dt>Known climb</dt>