Add rejected professionals tab and fix deny to keep record

- deny() now marks is_active:false instead of deleting the record
- New GET /professionals/rejected endpoint (pro_state:3)
- findPendingApprovals now filters only pro_state:1
- Admin list: third tab 'No aprobados' with approve/review actions

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

backend/src/professionals/professionals.controller.ts

@@ -30,6 +30,15 @@ export class ProfessionalsController {
     return this.pros.findPendingApprovals(page, limit);
   }
 
+  @Get('rejected')
+  @UseGuards(JwtAuthGuard)
+  @ApiBearerAuth()
+  findRejected(@Req() req) {
+    const page = +(req.query.page || 1);
+    const limit = +(req.query.limit || 20);
+    return this.pros.findRejected(page, limit);
+  }
+
   @Post(':id/approve')
   @UseGuards(JwtAuthGuard)
   @ApiBearerAuth()