fix(token): remove duplicate placeholder text from date inputs

The label already shows '从'/'到', so data-i18n-ph on inputs
caused duplicate text display. Removed placeholder attributes.

frontends/desktop/static/index.html

@@ -196,9 +196,9 @@
             <div class="page-title" data-i18n="page.token.title"></div>
             <div class="tok-filter">
               <label data-i18n="tok.from"></label>
-              <input type="text" id="tok-since" class="tok-date" readonly data-i18n-ph="tok.from">
+              <input type="text" id="tok-since" class="tok-date" readonly>
               <label data-i18n="tok.to"></label>
-              <input type="text" id="tok-until" class="tok-date" readonly data-i18n-ph="tok.to">
+              <input type="text" id="tok-until" class="tok-date" readonly>
               <button class="tok-reset" id="tok-reset" data-i18n="tok.reset"></button>
             </div>
             <div class="stat-row">