[ML 0.5/MVI.02.5] Initial Implementation of DeleteMessages Orchestration Flow

Description

Implement the DeleteMessages use case from scratch. This component orchestrates sub-use cases (MoveMessages, UpdateMessageFlags) and providers to execute the message deletion logic.

Goal

Develop a robust, reactive orchestrator that manages the complex deletion state machine using a Flow pipeline, ensuring high maintainability and compliance with single-exit-point constraints.

Acceptance Criteria

• Implements the DeleteMessages interface using Flow transformation operators (e.g., flatMapConcat).
• Successfully branches between "Soft Delete" and "Hard Delete" paths using the LocalDeleteOperationDecider.
• Triggers removeMessageNotification for all targeted messages.
• Emits all specific DeleteMessagesOutcome states as defined in the sealed interface.
• Testing: Unit tests using Fakes (orchestration tests) to verify that the Flow emits the correct sequence of DeleteMessagesOutcome states for both Soft and Hard delete paths.

Technical Requirements

• Must utilize the MoveMessages and UpdateMessageFlags flows to build the execution chain.
• Must satisfy Detekt's return-count and complexity rules.
• Error outcomes from sub-flows must be mapped to DeleteMessagesOutcome.Error and terminate the stream gracefully.