TEAMS.md Part 4. `team_activity` takes items from two sources and treats them
identically on the read path: core writes its own membership and rename items
with source='core', and a module pushes game items through
`ctx.teams.activity.push`, which stops throwing and starts working.
Core writing here too is deliberate — the rendering path is exercised by core's
own content from day one, so the feed is never empty on a deployment whose
module pushes nothing.
Three rules shape the model:
- core never composes a summary. It arrives already rendered and is stored
verbatim; core cannot phrase "gained 15,000 gold" for a game whose
vocabulary it does not know.
- visibility fails closed. An item with no stated visibility is `members`.
- a push never throws at its call site. It is called from inside a game-event
handler, and a storage problem of core's must not become the module's
control flow.
Core emits four of the five kinds §4.2 names — `core.forum.thread` has nothing
to emit it until the forum lands in phase 4 — and emits none of them for a
Team's FIRST roster: importing a 155-member guild is one Team arriving, not 155
people joining, and a join per member would bury every real event under the
import and reach the row cap on day one.
Retention ships with the feed rather than after someone notices. A nightly
worker applies an age horizon and a per-Team row cap, both settings; either
alone has a hole, since age lets one busy guild write a million rows inside the
window and a cap keeps a dead Team's feed forever.
The sync now reads member ROWS rather than keys, replacing the `memberKeys`
call rather than adding to it: the feed needs each changing member's display
name and prior `is_leader`, and the upsert is about to overwrite both.
Co-Authored-By: Claude <noreply@anthropic.com>
