Annotations / Notes

### User Story Description

As a user, I want to add annotations or notes to the 3D model by selecting a location and entering text in an input window, so that I can keep track of observations or comments directly on the model.

AVZ currently doesn't support this.

Please note in implementing this that there are 2 types of annotations that can be done: annotations that are located at XY positions in the rendering window, and annotations that are located at a set (X,Y,Z) geometrical space. The first ones stay in the same place when the user rotates / pans the model. The second type moves together with the model. The second type is more important for this user case. But still we need to have a way for the user to easily differentiate between them when creating and interacting with them.

A UX design for this feature can be found here:

https://www.figma.com/design/Hv5VN8vKsVNSueAWf4xo6i/AIEP?node-id=1117-5512&p=f&t=uP75aPtVN3hCAE17-0

### Acceptance Criteria

Open a session of VISOR.
The user can create an annotation set at a fixed X,Y location. When moving the model, the annotation stays at the same screen location.
Now create a second annotation set at a fixed (X,Y,Z) location. When moving the model, the annotation moves with the model itself.

Save a state file. Load a new session of VISOR. Load that state file. The annotations reappear with the same characteristics.

### Additional Links

_No response_

### Requires new or update to third party ? If "yes" add the name(s) and the version(s) of the Third Party Software.

No

### Name and Version for Third Parties

_No response_

Start by reviewing the linked Figma UX design and tracing the VISOR rendering, session, and state-file flows. Done means users can create both screen-fixed and model-fixed text annotations, distinguish them during interaction, and preserve their characteristics across saving and loading a state file.

Written by the indexing model from the issue text.