Add i18n localization to calendar filter component

- Add translation keys to filter.periods namespace:
  - filter.periods.today: Today period option
  - filter.periods.week: Week period option

- Localize shared/ui/filter/calendar.tsx:
  - Replace hardcoded "조회기간" with filter.period
  - Replace hardcoded "당일" with filter.periods.today
  - Replace hardcoded "일주일" with filter.periods.week
  - Replace hardcoded "1개월" with filter.periods.1month
  - Replace hardcoded "직접입력" with filter.periods.custom
  - Replace hardcoded "날짜 선택" with filter.selectDate

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

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

src/locales/en.json

@@ -91,6 +91,8 @@
           "issueNumber": "Issue Number"
         },
         "periods": {
+          "today": "Today",
+          "week": "1 Week",
           "currentMonth": "Current Month",
           "1month": "1 Month",
           "2months": "2 Months",

src/locales/ko.json

@@ -91,6 +91,8 @@
           "issueNumber": "발행번호"
         },
         "periods": {
+          "today": "당일",
+          "week": "일주일",
           "currentMonth": "당월",
           "1month": "1개월",
           "2months": "2개월",