fix: comprehensive security and type improvements from PR #20 review

Security Enhancements:
- Implemented proper rate limiting with automatic cleanup for /register and /forgot-password endpoints
- Added memory usage protection with MAX_ENTRIES limit (10000)
- Fixed rate limiter memory leaks by adding cleanup intervals
- Improved IP extraction with x-real-ip and x-client-ip header support

Code Quality Improvements:
- Refactored ProcessingStatusManager from individual functions to class-based architecture
- Maintained backward compatibility with singleton instance pattern
- Fixed TypeScript strict mode violations across the codebase
- Resolved all build errors and type mismatches

UI Component Fixes:
- Removed unused chart components (Charts.tsx, DonutChart.tsx)
- Fixed calendar component type issues by removing unused custom implementations
- Resolved theme provider type imports
- Fixed confetti component default options handling
- Corrected pointer component coordinate type definitions

Type System Improvements:
- Extended NextAuth types to support dual auth systems (regular and platform users)
- Fixed nullable type handling throughout the codebase
- Resolved Prisma JSON field type compatibility issues
- Corrected SessionMessage and ImportRecord interface definitions
- Fixed ES2015 iteration compatibility issues

Database & Performance:
- Updated database pool configuration for Prisma adapter compatibility
- Fixed pagination response structure in user management endpoints
- Improved error handling with proper error class usage

Testing & Build:
- All TypeScript compilation errors resolved
- ESLint warnings remain but no errors
- Build completes successfully with proper static generation

app/api/admin/trigger-processing/route.ts

@@ -4,7 +4,7 @@ import { getServerSession } from "next-auth";
 import { authOptions } from "../../../../lib/auth";
 import { prisma } from "../../../../lib/prisma";
 import { processUnprocessedSessions } from "../../../../lib/processingScheduler";
-import { ProcessingStatusManager } from "../../../../lib/processingStatusManager";
+import { getSessionsNeedingProcessing } from "../../../../lib/processingStatusManager";
 
 interface SessionUser {
   email: string;
@@ -65,11 +65,10 @@ export async function POST(request: NextRequest) {
         : 5;
 
     // Check how many sessions need AI processing using the new status system
-    const sessionsNeedingAI =
-      await ProcessingStatusManager.getSessionsNeedingProcessing(
-        ProcessingStage.AI_ANALYSIS,
-        1000 // Get count only
-      );
+    const sessionsNeedingAI = await getSessionsNeedingProcessing(
+      ProcessingStage.AI_ANALYSIS,
+      1000 // Get count only
+    );
 
     // Filter to sessions for this company
     const companySessionsNeedingAI = sessionsNeedingAI.filter(