feat(growth): same-day 1-day baselines for new videos

Let 1-day view growth use a zero baseline for videos published today, and the first successful sample for older videos ingested today, without mixing those into 7/30-day rankings.

reaction_board/migrations.py

@@ -244,6 +244,18 @@ MIGRATIONS: tuple[Migration, ...] = (
             "CREATE INDEX idx_visit_date ON visit(stat_date)",
         ),
     ),
+    Migration(
+        version=8,
+        name="snapshot open view",
+        statements=(
+            # 同日第一次成功采样的播放量，供近 1 日「入库后增量」做基准。
+            # 已有成功行无法找回被覆盖的入库值，只能把当前 view 当作开盘。
+            'ALTER TABLE snapshot ADD COLUMN view_open INTEGER',
+            "ALTER TABLE snapshot ADD COLUMN open_captured_at INTEGER",
+            'UPDATE snapshot SET view_open = "view", open_captured_at = captured_at '
+            "WHERE ok = 1 AND view_open IS NULL",
+        ),
+    ),
 )