feat(dashboard): show Claude usage per day/week instead of per session

Persists per-day token usage (usage_store, ~/.config/wsai/usage.json, survives
restarts) and surfaces it in status as claude_usage.{today,week}. The navbar now
shows two cards — 오늘 토큰 / 주간 토큰 (input+output, with per-card tooltips
breaking down input/output tokens and requests) — replacing the session-only
token count.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

wsai/monitor.py

@@ -194,10 +194,15 @@ class Monitor:
         with self._lock:
             s = dict(self._status)
         s["uptime_s"] = round(_now_wall() - s["started_wall"], 1)
+        from . import usage_store
+        s["claude_usage"] = usage_store.summary()  # 오늘 / 최근 7일 토큰
         return s
 
     def add_claude_usage(self, input_tokens: int, output_tokens: int) -> None:
-        """Accumulate one Claude call's token usage for the dashboard."""
+        """Record one Claude call's token usage (session counters + persisted
+        per-day store for the dashboard's 하루/일주일 사용량)."""
+        from . import usage_store
+        usage_store.record(input_tokens, output_tokens)
         with self._lock:
             self._status["claude_requests"] += 1
             self._status["claude_input_tokens"] += int(input_tokens or 0)