Remove SpaceStore singleton (#34088)

* Remove dead code

* Remove LegacyCallHandler singleton

Route via SDKContext to cut import cycles

* Remove SpaceStore singleton

Route via SDKContext to cut import cycles

* Fix tests

* Fix tests

* Fix tests

* Fix tests

* Iterate

* Post-merge fixup

* Iterate

apps/web/test/test-utils/test-utils.ts

@@ -49,6 +49,7 @@ import { EnhancedMap } from "../../src/utils/maps";
 import { type AsyncStoreWithClient } from "../../src/stores/AsyncStoreWithClient";
 import MatrixClientBackedSettingsHandler from "../../src/settings/handlers/MatrixClientBackedSettingsHandler";
 import { vi } from "../setup/adapter.ts";
+import { SDKContextClass } from "../../src/contexts/SDKContextClass.ts";
 
 /**
  * Stub out the MatrixClient, and configure the MatrixClientPeg object to
@@ -76,6 +77,8 @@ export function stubClient(): MatrixClient {
     peg.get = () => client;
     peg.safeGet = () => client;
     MatrixClientBackedSettingsHandler.matrixClient = client;
+    // @ts-ignore
+    SDKContextClass.instance._client = client;
     return client;
 }