feat(election): candidate voter analysis — Chart.js charts, cross-dimension insights

- New CandidateAnalysisComponent with Chart.js doughnut charts for all
  demographic/financial/social dimensions (gender, age, area, caste,
  sub-caste, religion, occupation, share-holding, tenure, loan, education,
  marital status, monthly income, savings account depth)
- Section 4: Multi-Dimension Voter Alignment card showing core base
  (caste + area cross-match), caste %, area %, and savings engagement
- Candidate board: added Analyse button linking to analysis page
- Hero header, KPI strip, 4 dashboard sections with hover charts

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

src/app/election/components/candidate-board/candidate-board.component.scss

@@ -303,8 +303,33 @@
 .candidate-actions {
   display: flex;
   justify-content: center;
+  gap: 6px;
   margin-top: 6px;
 
+  .btn-analyse {
+    display: inline-flex;
+    align-items: center;
+    gap: 3px;
+    background: #eff6ff;
+    color: #2563eb;
+    border: 1px solid #bfdbfe;
+    padding: 4px 10px;
+    border-radius: 6px;
+    font-size: 11px;
+    text-decoration: none;
+    cursor: pointer;
+
+    mat-icon {
+      font-size: 13px;
+      height: 13px;
+      width: 13px;
+    }
+
+    &:hover {
+      background: #dbeafe;
+    }
+  }
+
   .btn-remove {
     display: inline-flex;
     align-items: center;