System Updates: Renamed From Activity

The company-wide feed of human-written notes on entities is now called Updates. In the system sidebar it reads Updates rather than Activity, and its page has moved from /system/activity to /system/updates. Bookmarks pointed at the old URL will not resolve.

Activity is now reserved for system-generated logs — the ones on entity detail pages and the Recent activity card on the dashboard — so the two feeds are named for what they are. Same notes, same replies, same feed.