feat(stats): add note ID resolution and session event handling improvements

- Add note ID resolution through merge redirects in stats API
- Build Anki note previews using configured field names
- Add session event helpers for merged note dedup and stable request keys
- Refactor SessionDetail to prevent redundant note info requests
- Add session event popover and API client tests

stats/src/hooks/useSessions.ts

@@ -1,5 +1,6 @@
 import { useState, useEffect } from 'react';
 import { getStatsClient } from './useStatsApi';
+import { SESSION_CHART_EVENT_TYPES } from '../lib/session-events';
 import type { SessionSummary, SessionTimelinePoint, SessionEvent } from '../types/stats';
 
 export function useSessions(limit = 50) {
@@ -65,7 +66,7 @@ export function useSessionDetail(sessionId: number | null) {
     const client = getStatsClient();
     Promise.all([
       client.getSessionTimeline(sessionId),
-      client.getSessionEvents(sessionId),
+      client.getSessionEvents(sessionId, 500, [...SESSION_CHART_EVENT_TYPES]),
       client.getSessionKnownWordsTimeline(sessionId),
     ])
       .then(([nextTimeline, nextEvents, nextKnownWords]) => {