[fix](trx-frontend): fix CW audio picker and bookmark add button

Use an audio-window tone picker for CW with exact click-to-tone mapping.
Make + Add Bookmark inherit the shared button style.

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html

@@ -565,7 +565,7 @@
         </div>
         <div class="cw-tone-picker">
           <div class="cw-tone-picker-head">
-            <span>CW Tone Picker</span>
+            <span>CW Audio Tone Picker</span>
             <small id="cw-tone-range">--</small>
           </div>
           <canvas id="cw-tone-waterfall" width="320" height="56" aria-label="CW tone selector"></canvas>