feat: filter Find Work by repository and label (Closes #681)

frontend/index.html

@@ -541,6 +541,14 @@
       <button id="clear-find-work-search" type="button" hidden>Clear</button></div>
       <span id="find-work-match-status" class="small" aria-live="polite"></span>
     </form>
+    <details class="find-work-filters" id="find-work-filters">
+      <summary>Filter work <span id="find-work-filter-count" class="small"></span></summary>
+      <div class="find-work-filter-panel" aria-label="Filter available work">
+        <fieldset><legend>Repositories</legend><div id="find-work-repository-filters" class="find-work-filter-options"></div></fieldset>
+        <fieldset><legend>Labels</legend><div id="find-work-label-filters" class="find-work-filter-options"></div></fieldset>
+        <button id="clear-find-work-filters" type="button">Clear filters</button>
+      </div>
+    </details>
     <button class="fill-find-work-today" id="fill-find-work-today" type="button"
       aria-describedby="find-work-selection-status">Fill remaining Today slots</button>
     <div id="find-work-status" class="small" aria-live="assertive">Open Find Work to load available issues.</div>