feat(actors): Implement UnregisterActorRemindersByType for bulk reminder cleanup

[WhitWaldo]

Summary

The Dapr runtime exposes an UnregisterActorRemindersByType RPC (defined in dapr.proto line 103) that unregisters all reminders for a given actor type, optionally scoped to a specific actor instance. The JS SDK does not currently implement this method.

Motivation

• SDK parity: Other Dapr SDKs expose this capability.
• Operational cleanup: Enables bulk removal of reminders during actor type deprecation, scaling events, or testing cleanup.
• Reduced boilerplate: Without this, users must enumerate reminders via ListActorReminders and individually unregister each one.

Proto Definition

From src/proto/dapr/proto/runtime/v1/actors.proto:

// UnregisterActorRemindersByTypeRequest is the message to unregister an actor
// reminders by the given type. Optional actor_id can be provided to limit the
// scope of the operation to a specific actor instance.
message UnregisterActorRemindersByTypeRequest {
  string actor_type = 1;
  optional string actor_id = 2;
}

message UnregisterActorRemindersByTypeResponse {}

Proposed API Surface

// IClientActor interface addition:
unregisterActorRemindersByType(actorType: string, actorId?: ActorId): Promise<void>;

Implementation Notes

• gRPC path: Call UnregisterActorRemindersByType on the Dapr service via ConnectRPC client.
• HTTP path: DELETE /v1.0/actors/{actorType}/reminders (with optional ?actorId= query param — verify against Dapr runtime HTTP API).
• The actor_id parameter is optional. When provided, only reminders for that specific actor instance are removed. When omitted, all reminders for the entire actor type are removed — this should be clearly documented as a potentially destructive operation.

Acceptance Criteria

• unregisterActorRemindersByType added to IClientActor interface
• gRPC implementation
• HTTP implementation
• Unit tests
• E2E tests (register several reminders, bulk unregister, verify they're gone)
• Clear JSDoc documentation warning about the destructive nature when actorId is omitted

References

• Dapr Actors API reference: https://docs.dapr.io/reference/api/actors_api/
• Proto: src/proto/dapr/proto/runtime/v1/dapr.proto line 103
• Messages: src/proto/dapr/proto/runtime/v1/actors.proto lines 160-168