Missing directional context for user when using maps

### Description

When viewing the map, there is currently no indication of which direction the user is facing (heading). This creates spatial disorientation, forcing users to walk in a direction just to see which way their location dot moves on the screen. Computers lack the sensors for this, and not all phones have them either. The indicator should appear whenever it is available.

This refers to the last image (blue beam)

The user would also see the accuracy radius, like you do with google maps.

### Checklist
- **Does it need UI/UX design?**
- [x] Yes. Describe the UI/UX requirements or attach a Figma link in the "Design" section.
- [ ] No
- **Does it need API design?**
- [ ] Yes. Specify the endpoints, methods, or data structures needed.
- [x] No
- **Does it need design around state flow?**
- [ ] Yes. Outline the state flow requirements.
- [x] No
- **Does it need a test plan?**
- [ ] Yes. Add the test plan as a comment in this task or attach the document.
- [x] No
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### User Stories

- **As a** [user type],
**I want** [functionality],
**so that** [benefit].

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### Design

- [Figma](https://www.figma.com/design/6v0NnvayfDlaQhYpjv37Bn/ODK-Web-Forms?node-id=4203-4&t=Nt9mQd0OXi9h8ume-1)

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### Dependencies

- https://github.com/getodk/web-forms/issues/561

Review the map view and linked dependency #561 first, then compare the requested behavior with the provided Figma design. Confirm how the location dot, heading availability, and accuracy radius should appear, and verify that the directional indicator and radius are shown only when supported.

Written by the indexing model from the issue text.