feat(board): support natural-week SQL templates and harden prompt

src/components/BoardManager.tsx

@@ -238,12 +238,21 @@ const resolveSqlTemplate = (sql: string) => {
 
   const todayStart = new Date(now)
   todayStart.setHours(0, 0, 0, 0)
+  const mondayOffset = (todayStart.getDay() + 6) % 7
+  const thisWeekStart = at(-mondayOffset)
+  thisWeekStart.setHours(0, 0, 0, 0)
+  const lastWeekStart = at(-mondayOffset - 7)
+  lastWeekStart.setHours(0, 0, 0, 0)
 
   return sql
     .split("{{now}}")
     .join(formatIso(now))
     .split("{{today_start}}")
     .join(formatIso(todayStart))
+    .split("{{this_week_start}}")
+    .join(formatIso(thisWeekStart))
+    .split("{{last_week_start}}")
+    .join(formatIso(lastWeekStart))
     .split("{{since_7d}}")
     .join(formatIso(at(-7)))
     .split("{{since_30d}}")

src/i18n/locales/en-US.json

@@ -618,7 +618,7 @@
       "todayAnswered": "Today"
     },
     "sqlPlaceholder": "Enter SQL (single SELECT / WITH query only)",
-    "templateHint": "Template variables: {{today_start}}, {{since_7d}}, {{since_30d}}, {{now}}",
+    "templateHint": "Template variables: {{today_start}}, {{this_week_start}}, {{last_week_start}}, {{since_7d}}, {{since_30d}}, {{now}}",
     "templateDescription": "Use template variables directly in SQL. They will be replaced with ISO timestamps at runtime for both SQLite and PostgreSQL.",
     "saving": "Saving...",
     "saveFailed": "Failed to save boards",

src/i18n/locales/zh-CN.json

@@ -618,7 +618,7 @@
       "todayAnswered": "今日回答"
     },
     "sqlPlaceholder": "输入 SQL（仅支持单条 SELECT / WITH 查询）",
-    "templateHint": "支持时间模板变量：{{today_start}}、{{since_7d}}、{{since_30d}}、{{now}}",
+    "templateHint": "支持时间模板变量：{{today_start}}、{{this_week_start}}、{{last_week_start}}、{{since_7d}}、{{since_30d}}、{{now}}",
     "templateDescription": "可直接在 SQL 中使用模板变量，运行时会自动替换为 ISO 时间，兼容 SQLite 与 PostgreSQL。",
     "saving": "保存中...",
     "saveFailed": "保存看板失败",