fix(frontend): Fix critical type safety issues from code review

Address all Critical and High Priority issues identified in frontend code review report:

Critical Issues Fixed:
- Created unified logger utility (lib/utils/logger.ts) to replace all console.log statements
- Consolidated User type definitions - removed duplicate from authStore, using single source from types/user.ts
- Eliminated 'any' types in API client - added proper generic types with AxiosRequestConfig
- Fixed SignalR ConnectionManager - replaced 'any' with generic types <T>
- Created API error types (lib/types/errors.ts) with ApiError and getErrorMessage helper
- Fixed IssueCard component - removed all type assertions, created discriminated union types for Kanban items
- Added React.memo to IssueCard for performance optimization
- Added proper ARIA labels and accessibility attributes to IssueCard

High Priority Issues Fixed:
- Fixed hardcoded user ID in CreateProjectDialog - now uses actual user from authStore
- Added useCallback to CreateProjectDialog onSubmit handler
- Fixed error handlers in use-epics.ts - replaced 'any' with ApiError type
- Updated all error handling to use logger and getErrorMessage

Type Safety Improvements:
- Created KanbanItem discriminated union (KanbanEpic | KanbanStory | KanbanTask) with proper type guards
- Added 'never' types to prevent invalid property access
- Fixed User interface to include all required fields (createdAt, updatedAt)
- Maintained backward compatibility with LegacyKanbanBoard for existing code

Files Changed:
- lib/utils/logger.ts - New centralized logging utility
- lib/types/errors.ts - New API error types and helpers
- types/user.ts - Consolidated User type with TenantRole
- types/kanban.ts - New discriminated union types for type-safe Kanban items
- components/features/kanban/IssueCard.tsx - Type-safe with React.memo
- components/features/projects/CreateProjectDialog.tsx - Fixed hardcoded user ID, added useCallback
- lib/api/client.ts - Eliminated 'any', added proper generics
- lib/signalr/ConnectionManager.ts - Replaced console.log, added generics
- lib/hooks/use-epics.ts - Fixed error handler types
- stores/authStore.ts - Removed duplicate User type
- lib/hooks/useAuth.ts - Added createdAt field to User

TypeScript compilation: ✅ All type checks passing (0 errors)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

lib/utils/logger.ts

@@ -0,0 +1,88 @@
+/**
+ * Unified logging utility for ColaFlow
+ * Provides type-safe logging with environment-aware behavior
+ */
+
+type LogLevel = 'debug' | 'info' | 'warn' | 'error';
+
+interface LoggerConfig {
+  isDevelopment: boolean;
+  enableDebug: boolean;
+  enableInfo: boolean;
+}
+
+class Logger {
+  private config: LoggerConfig;
+
+  constructor() {
+    this.config = {
+      isDevelopment: process.env.NODE_ENV === 'development',
+      enableDebug: process.env.NODE_ENV === 'development',
+      enableInfo: process.env.NODE_ENV === 'development',
+    };
+  }
+
+  /**
+   * Debug level logging - only in development
+   */
+  debug(message: string, data?: unknown): void {
+    if (this.config.enableDebug) {
+      console.log(`[DEBUG] ${message}`, data !== undefined ? data : '');
+    }
+  }
+
+  /**
+   * Info level logging - only in development
+   */
+  info(message: string, data?: unknown): void {
+    if (this.config.enableInfo) {
+      console.info(`[INFO] ${message}`, data !== undefined ? data : '');
+    }
+  }
+
+  /**
+   * Warning level logging - always logged
+   */
+  warn(message: string, data?: unknown): void {
+    console.warn(`[WARN] ${message}`, data !== undefined ? data : '');
+  }
+
+  /**
+   * Error level logging - always logged
+   * In production, this should integrate with error tracking services
+   */
+  error(message: string, error?: unknown): void {
+    console.error(`[ERROR] ${message}`, error !== undefined ? error : '');
+
+    // In production, send to error tracking service
+    if (!this.config.isDevelopment) {
+      // TODO: Integrate with Sentry/DataDog/etc
+      // errorTracker.captureException(error, { message });
+    }
+  }
+
+  /**
+   * Log with context information for better debugging
+   */
+  logWithContext(level: LogLevel, message: string, context?: Record<string, unknown>): void {
+    const contextString = context ? JSON.stringify(context) : '';
+
+    switch (level) {
+      case 'debug':
+        this.debug(message, context);
+        break;
+      case 'info':
+        this.info(message, context);
+        break;
+      case 'warn':
+        this.warn(message, context);
+        break;
+      case 'error':
+        this.error(message, context);
+        break;
+    }
+  }
+}
+
+// Export singleton instance
+export const logger = new Logger();