feat(election): Board of Directors module — appoint, manage, and track elected directors

- New director-board component: 2-step drawer (pick WON candidate → fill appointment details)
- Pending appointments section: highlights WON candidates not yet given a designation
- mat-datepicker for all date fields; tenure end auto-fills to +5 years from start
- Frontend validation: required field indicators + inline mat-error on submit attempt
- Past dates disabled via [min]="today" on all date pickers
- mat-select for Designation and Status (CBS outline style)
- Election service: appointDirector, updateDirector, deleteDirector, getDirectors, getPendingDirectors
- Route added: /election/directors; nav link in election dashboard
- Error handler: suppress 404 toast for /election/directors (backend not yet deployed guard)

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

src/app/core/http/error-handler.interceptor.ts

@@ -53,7 +53,8 @@ export class ErrorHandlerInterceptor implements HttpInterceptor {
 
     const isClientImageRequest = request.url.includes('/clients/') && request.url.includes('/images');
     const isClientKycRequest = request.url.match(/\/clients\/\d+\/kyc$/);
-    const isSilentRequest = isClientImageRequest || isClientKycRequest;
+    const isDirectorRequest = request.url.includes('/election/directors');
+    const isSilentRequest = isClientImageRequest || isClientKycRequest || isDirectorRequest;
 
     if (!environment.production && !isSilentRequest) {
       log.error(`Request Error: ${errorMessage}`);