* migrated a lot of unit tests to Swift Testing and added a new implementation for deferred fulfillment
more tests migration
Cleaned the code manually to establish some good patterns
more code improvements
some more code improvements
removed empty tests
update project
* more pr suggestions and cleanups
* removed the TestSetup pattern
* fixing claude not reusing tests
* pr suggestion + added indent rule to swiftformat so that we can prevent AIs to change that
* Introduce a `TimelineItemThreadSummary` object to hold details about threads starting from that particular item
This patch introduces a thread summary object that will be available on main timeline messages that are the root for a given thread.
It currently provides the latest message content and sender for that thread but it will grow to provide info on the number of replies, unreads etc.
It also add a new UI component called `TimelineThreadSummaryView` that makes use of this data and is in turn used by the bubbled styler to render it in the timeline.
The rest of the PR is about refactoring on the `RoomTimelineItemFactory` so that replies and thread summaries use similar paths and builders.
* Add a feature flag for threads
* Address PR comments
* Converge on single implementation for message previews
