[SDK] update state structure (less duplication, one state enum)

- remove media from LocalMembership file

sdk/src/matrixrtc/HomeserverConnected.ts

@@ -29,6 +29,7 @@ import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { type ObservableScope } from "../reactive/ObservableScope";
 import { type Behavior } from "../reactive/Behavior";
 import { defaultSessionTimings } from "../config";
+import { type MatrixDisconnectReason } from "../api";
 
 type NodeEventHandler = (...args: unknown[]) => void;
 
@@ -37,22 +38,16 @@ interface NodeStyleEventEmitter {
   removeListener(eventName: string | symbol, handler: NodeEventHandler): this;
 }
 
-export type HomeserverDisconnectReason = "sync" | "membership" | "probablyLeft";
-
 export interface HomeserverConnected {
-  /**
-   * Emits `[true, null]` when the homeserver connection is healthy, or
-   * `[false, reason]` when one of the three sub-conditions fails.
-   */
-  combined$: Behavior<[boolean, HomeserverDisconnectReason | null]>;
-  rtsSession$: Behavior<Status>;
+  /** Null while the homeserver connection is healthy, the first failing link otherwise. */
+  disconnectReason$: Behavior<MatrixDisconnectReason | null>;
 }
 
 /**
  * Behavior representing whether we consider ourselves connected to the Matrix homeserver
  * for the purposes of a MatrixRTC session.
  *
- * `combined$` emits `null` when all conditions are satisfied, or the first failing
+ * `disconnectReason$` emits `null` when all conditions are satisfied, or the first failing
  * reason (priority: syncing > membershipConnected > certainlyConnected):
  * 1. Sync loop is not in SyncState.Syncing (after grace period) → "sync"
  * 2. membershipStatus !== Status.Connected → "membership"
@@ -118,26 +113,19 @@ export function createHomeserverConnected$(
     map(() => matrixRTCSession.probablyLeft !== true),
   );
 
-  const combined$ = scope.behavior(
+  const disconnectReason$ = scope.behavior(
     combineLatest([syncing$, membershipConnected$, certainlyConnected$]).pipe(
-      map(
-        ([syncing, membership, certainly]): [
-          boolean,
-          HomeserverDisconnectReason | null,
-        ] => {
-          if (!syncing) return [false, "sync"];
-          if (!membership) return [false, "membership"];
-          if (!certainly) return [false, "probablyLeft"];
-          return [true, null];
-        },
-      ),
-      tap(([connected, reason]) => {
-        logger.info(
-          `Homeserver connected update: ${connected ? "connected" : reason}`,
-        );
+      map(([syncing, membership, certainly]): MatrixDisconnectReason | null => {
+        if (!syncing) return "sync";
+        if (!membership) return "membership";
+        if (!certainly) return "probablyLeft";
+        return null;
+      }),
+      tap((reason) => {
+        logger.info(`Homeserver connected update: ${reason ?? "connected"}`);
       }),
     ),
   );
 
-  return { combined$, rtsSession$ };
+  return { disconnectReason$ };
 }