Stats: activity heatmap as a rolling window of the last 14 days

One row per calendar day (today at the bottom) instead of weekdays
aggregated over the selected range.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/store.rs

@@ -433,7 +433,7 @@ impl Store {
             |r| agg_row(r, 0),
         )?;
 
-        let grouped = |key_sql: &str, key_name: &str| -> Result<Vec<Value>> {
+        let grouped_in = |from: i64, key_sql: &str, key_name: &str| -> Result<Vec<Value>> {
             let mut stmt = conn.prepare(&format!(
                 "SELECT {key_sql}, {AGG} FROM usage WHERE ts >= ?1 AND ts < ?2 AND ?3 = ?3
                  AND (?4 IS NULL OR user_id = ?4) GROUP BY 1 ORDER BY 1"
@@ -451,6 +451,7 @@ impl Store {
                 .collect::<rusqlite::Result<Vec<_>>>()?;
             Ok(rows)
         };
+        let grouped = |key_sql: &str, key_name: &str| grouped_in(from, key_sql, key_name);
 
         let day_sql = "strftime('%Y-%m-%d', (ts + ?3) / 1000, 'unixepoch')";
         let by_day = grouped(day_sql, "day")?;
@@ -461,10 +462,11 @@ impl Store {
             "COALESCE((SELECT username FROM users WHERE users.id = usage.user_id), '(none)')",
             "user",
         )?;
-        // Heatmap: weekday (0 = Sunday) x hour of day.
-        let heatmap = grouped(
-            "CAST(strftime('%w', (ts + ?3) / 1000, 'unixepoch') AS INTEGER) * 24 + \
-             CAST(strftime('%H', (ts + ?3) / 1000, 'unixepoch') AS INTEGER)",
+        // Heatmap: rolling window of the last 14 days (local date + hour),
+        // independent of the selected range.
+        let heatmap = grouped_in(
+            to - 15 * 86_400_000,
+            "strftime('%Y-%m-%d %H', (ts + ?3) / 1000, 'unixepoch')",
             "slot",
         )?;
         let by_day_model = {