Major refactor into type safe TS

With a risk oof rolling it all back

src/core/EventBus.ts

@@ -59,14 +59,14 @@ export class EventBus implements IEventBus {
   /**
    * Emit an event via DOM CustomEvent
    */
-  emit(eventType: string, detail: any = {}): boolean {
+  emit(eventType: string, detail: unknown = {}): boolean {
     // Validate eventType
-    if (!eventType || typeof eventType !== 'string') {
+    if (!eventType) {
       return false;
     }
 
     const event = new CustomEvent(eventType, {
-      detail,
+      detail: detail ?? {},
       bubbles: true,
       cancelable: true
     });
@@ -78,7 +78,7 @@ export class EventBus implements IEventBus {
 
     this.eventLog.push({
       type: eventType,
-      detail,
+      detail: detail ?? {},
       timestamp: Date.now()
     });
 
@@ -89,7 +89,7 @@ export class EventBus implements IEventBus {
   /**
    * Log event with console grouping
    */
-  private logEventWithGrouping(eventType: string, detail: any): void {
+  private logEventWithGrouping(eventType: string, detail: unknown): void {
     // Extract category from event type (e.g., 'calendar:datechanged' → 'calendar')
     const category = this.extractCategory(eventType);
     
@@ -108,7 +108,7 @@ export class EventBus implements IEventBus {
    * Extract category from event type
    */
   private extractCategory(eventType: string): string {
-    if (!eventType || typeof eventType !== 'string') {
+    if (!eventType) {
       return 'unknown';
     }