Updates build config and removes unused dependencies

Migrates from Brandi DI to @novadi/core dependency injection
Simplifies project structure by removing deprecated modules
Adds Novadi unplugin to esbuild configuration for enhanced build process

src/utils/DateService.ts

@@ -494,16 +494,4 @@ export class DateService {
 
     return { valid: true };
   }
-  
-  /**
-   * Check if event spans multiple days
-   * @param start - Start date or ISO string
-   * @param end - End date or ISO string
-   * @returns True if spans multiple days
-   */
-  public isMultiDay(start: Date | string, end: Date | string): boolean {
-    const startDate = typeof start === 'string' ? this.parseISO(start) : start;
-    const endDate = typeof end === 'string' ? this.parseISO(end) : end;
-    return !this.isSameDay(startDate, endDate);
-  }
 }