feat(stats): add v1 immersion stats dashboard (#19)

src/core/services/immersion-tracker/reducer.ts

@@ -15,11 +15,11 @@ export function createInitialSessionState(
     totalWatchedMs: 0,
     activeWatchedMs: 0,
     linesSeen: 0,
-    wordsSeen: 0,
     tokensSeen: 0,
     cardsMined: 0,
     lookupCount: 0,
     lookupHits: 0,
+    yomitanLookupCount: 0,
     pauseCount: 0,
     pauseMs: 0,
     seekForwardCount: 0,
@@ -30,6 +30,7 @@ export function createInitialSessionState(
     lastPauseStartMs: null,
     isPaused: false,
     pendingTelemetry: true,
+    markedWatched: false,
   };
 }
 
@@ -50,16 +51,6 @@ export function sanitizePayload(payload: Record<string, unknown>, maxPayloadByte
   return json.length <= maxPayloadBytes ? json : JSON.stringify({ truncated: true });
 }
 
-export function calculateTextMetrics(value: string): {
-  words: number;
-  tokens: number;
-} {
-  const words = value.split(/\s+/).filter(Boolean).length;
-  const cjkCount = value.match(/[\u3040-\u30ff\u4e00-\u9fff]/g)?.length ?? 0;
-  const tokens = Math.max(words, cjkCount);
-  return { words, tokens };
-}
-
 export function secToMs(seconds: number): number {
   const coerced = Number(seconds);
   if (!Number.isFinite(coerced)) return 0;