Update SDK to be consumed by Element Call's CallViewModel

Update the public API to export the primitives and operators the call
model needs, and change `LocalMediaInputs` from observable flags to
immediate booleans with imperative setters. Add session timings, media
quality and capture settings as configuration options, and allow the
host to override the transport discovery with explicit URLs.

sdk/index.ts

@@ -10,18 +10,49 @@ Please see LICENSE in the repository root for full details.
  *
  * MatrixRTC sessions with LiveKit media, without Element Call's UI: the call
  * model Element Call's own view model is built on, for hosts that want to
- * build a different one. The design and the migration from Element Call's
- * `CallViewModel` are in `sdk-plan.md` at the repository root.
+ * build a different one. The design is in `SdkArchitecture.md` next to this
+ * file.
  */
 
-// Shared with Element Call. They live in `src` until the view model consumes
-// the SDK, at which point they move here; a consumer gets them from this
-// module either way.
 export { type Behavior, constant } from "./src/reactive/Behavior";
-export { ObservableScope } from "./src/reactive/ObservableScope";
-export { E2eeType } from "./src/encryption";
-export { type EncryptionSystem } from "./src/encryption";
-export { MatrixRTCMode } from "./src/config";
+export {
+  Epoch,
+  mapEpoch,
+  ObservableScope,
+  trackEpoch,
+} from "./src/reactive/ObservableScope";
+export {
+  filterBehavior,
+  finalizeValue,
+  generateItems,
+  generateItemsWithEpoch,
+  pauseWhen,
+} from "./src/reactive/observable";
+export { E2eeType, type EncryptionSystem } from "./src/encryption";
+export {
+  defaultMediaQuality,
+  defaultSessionTimings,
+  type DelayedLeaveTimings,
+  MatrixRTCMode,
+  type MediaQuality,
+  type SessionTimings,
+} from "./src/config";
+export {
+  ErrorCategory,
+  ErrorCode,
+  FailToGetOpenIdToken,
+  FailToStartLivekitConnection,
+  InsufficientCapacityError,
+  LivekitConnectionError,
+  MatrixRTCTransportMissingError,
+  MembershipManagerError,
+  NoMatrix2AuthorizationService,
+  PeerConnectionTimeoutError,
+  SFURoomCreationRestrictedError,
+  UnknownCallError as UnknownRTCError,
+} from "./src/errors";
 
 export * from "./src/api";
 export { createMatrixRTCClient } from "./src/session/MatrixRTCClient";
+// For a developer panel to check a transport url before using it
+export { getSFUConfigWithOpenID as authenticateWithTransport } from "./src/session/openIDSFU";