fix(viewer): keep a window turned the way its device's screen is

[Mastersam07]

What: A window now keeps turned the way its device's screen is, whoever turns the device. A turn from Device Hub or from the guest used to leave the window where it was, and a turn of our own that the screen refused (upside down on a Face ID phone) or that a foldable never received left the window turned while the screen was not. The window reads the display report after the screens announce a change, takes back its own turn if the screen does not follow, holds still while a foldable's hinge moves, and Rotate Left and Right count on from the turn last asked for, so upside down on a Face ID phone is passed on the next press.

Verification:

• swift test: all unit tests pass, including 12 new ones for the watcher: the Duo's measured panel angles, a moment on the way through a fold not believed, a lagging report not counted as a turn back, a refused turn restated, a late turn reported once.
• Integration on an iPhone Duo (iOS 27.1) and an iPhone 17 (iOS 27.0), each run twice and more:
  • Duo, turned from outside through its own control (Device Hub's route): the window followed all four turns in 0.5 to 0.8 s. Turned from the window: the screen took each turn and the window never moved off it. Shut and opened while held landscape left: the window stayed put over 90 samples each way.
  • iPhone, turned from outside with devicectl device orientation set: the window followed both landscapes in 0.6 to 1.0 s and a click on its upper left landed on the upper left of the guest. Held upside down, and held sideways at the home screen: the screen stays upright and so does the window. Our own turn to upside down: the window showed it, went back to portrait when the screen refused, and the next rotate turned to landscape left.
• The probes behind the design: the screens announce a turn within about 150 ms, only when the screen itself turns; the report catches up 0.5 to 1.2 s later; a foldable's report names the old panel with the new panel's turn for about 0.2 to 0.35 s while unfolding; the report's own panel angle reads 0, so the device type's angles are used (inner panel 270, cover 0).

Follow-ups:

• Merges cleanly with the open performance check pull request, which also changes the orientation read at open.
• Rotate still offers upside down on devices that refuse it; it is now passed on the next press, but skipping it would save the press.
• Orientation lock is not read or shown.