feat(election): candidate photos/symbols, voting interface, withdrawal, live vote counts

- Candidate board: show client profile photos and election symbols via CBS ContentStore
  (lazy-fetch base64 via GET /election/{id}/candidate/{id}/symbol), zoom/drag viewer
- Candidate board: live vote count badge per candidate (VOTING_OPEN/CLOSED only)
- Election dashboard: total voters/votes chips on VOTING_OPEN election cards
- Voting interface: fix candidates not loading (paged response .content extraction),
  lazy-load candidate photos and symbols, gold-bordered symbol on ballot card
- Nomination withdrawal: implement withdraw button in nomination-detail and nomination-list
- ImagePreviewDialogComponent: DomSanitizer support for data: URLs
- election.service: uploadCandidateSymbol (FormData), getCandidateSymbol, getClientImage,
  getVoteSummary methods
- main.scss: ipd-dialog / ipd-backdrop styles for image preview dialog

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

src/app/election/components/election-dashboard/election-dashboard.component.html

@@ -28,7 +28,7 @@
     <div class="stats-row">
       <div class="stat-card">
         <span class="stat-value">{{ totalElements }}</span>
-        <span class="stat-label">Total Elections</span>
+        <span class="stat-label">Total</span>
       </div>
       <div class="stat-card">
         <span class="stat-value">{{ countByStatus('ACTIVE') }}</span>
@@ -81,6 +81,16 @@
             @if (election.description) {
               <p class="description">{{ election.description }}</p>
             }
+
+            @if (voteSummaryMap[election.id]) {
+              <div class="voter-count-row">
+                <span class="voter-count-chip">
+                  <mat-icon>how_to_vote</mat-icon>
+                  {{ voteSummaryMap[election.id].totalVoters }} members voted
+                </span>
+                <span class="vote-total-chip"> {{ voteSummaryMap[election.id].totalVotes }} total votes </span>
+              </div>
+            }
           </div>
 
           <div class="card-actions">