Address privacy review feedback

[marcoscaceres]

Closes #262
Closes #261
Closes #260
Closes #259
Closes #252

This pull request updates the screen orientation specification to strengthen privacy protections and clarify requirements for event delivery and locking behavior. The changes focus on restricting orientation events and locking to documents that are both visible and have user attention, and introduce new anti-fingerprinting mitigations.

Privacy and Fingerprinting Mitigations

• Added explicit warnings that differences in user preferences or platform capabilities affecting orientation lock failures may be used for fingerprinting. (index.html, index.htmlL727-R730)
• Revised fingerprinting mitigation language to clarify that both orientation type and angle are potential vectors, and introduced a new section detailing event delivery restrictions and anti-fingerprinting strategies. (index.html, index.htmlL914-R956)

Event Delivery and Locking Behavior

• Updated multiple algorithms and developer notes to require that orientation events and locking only occur for documents that are "fully active descendants of a top-level traversable with user attention," replacing previous checks based solely on visibility state. (index.html, [1] [2] [3]
• Changed the requirement for using ScreenOrientation.lock() in fullscreen contexts from "SHOULD" to "MUST", emphasizing that this restriction helps prevent fingerprinting via user agent behavior. (index.html, index.htmlL868-R876)

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Preview | Diff

[marcoscaceres]

@bvandersloot-mozilla, would you mind having a look and let me know if you are satisfied?

[Copilot]

Pull Request Overview

Strengthens privacy protections and clarifies event delivery/locking by requiring orientation behavior only for documents that are fully active descendants of a top-level traversable with user attention, and by adding explicit anti-fingerprinting guidance.

• Replace visibility-only checks with a stronger “fully active descendant of a top-level traversable with user attention” gate for events and locking
• Elevate fullscreen pre-lock requirement from SHOULD to MUST to mitigate fingerprinting
• Add new privacy sections detailing event delivery restrictions and anti-fingerprinting mitigations

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[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 6 comments.

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[bvandersloot-mozilla]

These changes address the issues I filed! Thank you!

[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

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