feat(kanban): partition local queues by account

req: sync/020

req: auth/005

req: security/004

req: operations/002

examples/kanban/src/main.rs

@@ -428,6 +428,7 @@ async fn main() {
         .route("/events", get(events))
         .route("/sync-demo", get(sync_demo))
         .route("/sync.js", get(sync_js))
+        .route("/sync/context", get(sync_context))
         .route("/sync/commands", post(sync_command))
         .route("/sync/acknowledgements", get(sync_acknowledgements))
         .route("/sync/snapshot", get(sync_snapshot))
@@ -585,6 +586,23 @@ fn current_sync_principal(
     ))
 }
 
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct SyncContext {
+    account_partition: String,
+}
+
+// req: sync/020 req: auth/005
+async fn sync_context(
+    State(state): State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Json<SyncContext>, SyncRejection> {
+    let principal = current_sync_principal(&headers, &state.sync_sessions)?;
+    Ok(Json(SyncContext {
+        account_partition: format!("{}:{}", principal.tenant, principal.principal),
+    }))
+}
+
 fn authorize_sync_replay(
     principal: CurrentSyncPrincipal,
     card_id: u64,