Docs brought up to the code, from the golden-set review

[lana-20]

Reviewing the golden question set for the docs evaluation meant checking each answer against today's code. These are the docs and comments that had fallen behind it. Docs and code text only; no behavior changes.

Stale since a fix:

• The agent skill said taps in Safari's or a home-screen web app's page are refused, and that an agent cannot start a device. Taps land since CHALLENGES 248 and 290; `mobium boot` exists.
• The checks README's dialogs row, PWA row and Dialog Demo paragraph described accept and dismiss before CHALLENGES 305, and the PWA tap before 290.
• README's mobile-web row said iOS taps go through the native tree.
• ROADMAP's "Reading an iOS screen without `visible`" is marked done. It no longer says `map` always reads in full, which a screen of 1,000 elements has contradicted since CHALLENGES 258.

Wrong:

• SETUP offered `MOBIUM_SESSION` as a way to choose between two emulators. A call that names no device is refused when two are ready.
• The multi-touch refusal and its comment said a restart clears fingers left down. CHALLENGES 86 measured that it does not, and that a two-finger tap does. The iOS remedy for press-tap now says Android 15 or earlier.
• The `Focused` comment said Android only; iOS has filled it since 297.

Missing:

• SHUTDOWN now says how `mobium shutdown` ends a frozen emulator (CHALLENGES 285).
• BACK.md's iOS section now points to `press back --gesture`.
• README and APP-TYPES list Ice Cubes, Pocket Casts and Kiwix among the iOS apps driven.

ROADMAP "Next" records three leads that need code or a decision:

• On an Apple TV, a dialog of three or more buttons names `button` as the remedy, and `button` taps.
• The docs say nothing about Android-derived platforms.
• Fingers left down on Android 16 and later still have no other way to land.

`make ci` passes.