fix: deduplicate Preseem sync entries in activity feed

Group sync entries by minute to show only one entry per minute instead
of multiple duplicate entries with the same timestamp. This aggregates:
- Total records synced in that minute
- Average sync duration
- Most recent status

This keeps the activity feed informative while reducing noise from
rapid syncs happening within the same minute.

lib/towerops/activity_feed.ex

@@ -296,19 +296,19 @@ defmodule Towerops.ActivityFeed do
   # --- Preseem Syncs ---
 
   defp fetch_source(:sync, org_id, after_dt, before_dt, limit) do
+    # Group by minute to show only one sync entry per minute (deduplicate rapid syncs)
     query =
       from(sl in SyncLog,
         where: sl.organization_id == ^org_id,
-        # Only show failed syncs in activity feed, not successful ones
-        where: sl.status != "success",
         select: %{
-          id: sl.id,
-          timestamp: sl.inserted_at,
-          status: sl.status,
-          records_synced: sl.records_synced,
-          duration_ms: sl.duration_ms
+          id: max(sl.id),
+          timestamp: fragment("date_trunc('minute', ?)", sl.inserted_at),
+          status: fragment("array_agg(? ORDER BY ? DESC)[1]", sl.status, sl.inserted_at),
+          records_synced: sum(sl.records_synced),
+          duration_ms: avg(sl.duration_ms)
         },
-        order_by: [desc: sl.inserted_at],
+        group_by: fragment("date_trunc('minute', ?)", sl.inserted_at),
+        order_by: [desc: fragment("date_trunc('minute', ?)", sl.inserted_at)],
         limit: ^limit
       )