fix(federation): address code review findings for FED-009

- Resolve homeUserId from DB in sendFederatedCallStart/End (not raw userId)
- Clear existing timeout in createFederatedCall before overwriting
- Clear federatedCallToken/Url in leaveVoice and handleForceDisconnect
- Remove unnecessary `as any` cast in relay processor

packages/web/src/stores/voiceStore.ts

@@ -482,6 +482,8 @@ export const useVoiceStore = create<VoiceState>()(
             focusedParticipantId: null,
             activeDmCall: null,
             outgoingCall: null,
+            federatedCallToken: null,
+            federatedCallUrl: null,
             deafenedUserIds: new Set(),
             participantMutes: new Map(),
             streamVolumes: new Map(),
@@ -517,6 +519,8 @@ export const useVoiceStore = create<VoiceState>()(
           focusedParticipantId: null,
           activeDmCall: null,
           outgoingCall: null,
+          federatedCallToken: null,
+          federatedCallUrl: null,
           deafenedUserIds: new Set(),
           participantMutes: new Map(),
           streamVolumes: new Map(),