Screenshots wanted for the export walkthrough

[simons-plugins]

docs/INSTALL.md carries three <!-- SCREENSHOT WANTED --> markers. All need a real Indigo/iOS capture:

1. Manage Matter Exports… with the role menu open and an excluded device visible (so the — not exportable: <reason> labelling is shown).
2. The pairing page as it renders on an iPhone.
3. Apple Home's uncertified-accessory sheet — the moment users are most likely to abandon; the E8 reader-experience review called this the single most reassuring image we could add.

Requires Simon (his server, his phone).