FEATURES.md and the touch gestures were written at the same time on separate
branches, so the inventory of everything ihasmail does landed knowing about
none of them: the mobile layout was still one line about a tab bar, and the
Appearance row of the settings table did not mention the two settings that
had just been added to it.
The gestures get a section of their own under Layout rather than a bullet,
because the interesting part is not the list of five -- it is why they are
gated on `(pointer: coarse)` rather than on width, why a direction with no
meaning in this folder refuses to move rather than moving and doing nothing,
and why the axis lock gives a diagonal drag to the scroller. The same
reasoning is in the code; this is where somebody reads it without opening
lib/touch.ts.
Also here: the `dvh` and safe-area notes alongside the mobile layout, a long
press added to the list's multi-select bullet, and a short note in the
settings-sync section on why the swipe actions follow the account despite
looking like a per-device setting.
The feature list lived in three places that each answered a different question: the site sells it, the docs teach the parts that surprise people, and the README summarises both in a paragraph. Nothing said, in one place and at full detail, what is actually built -- so evaluating ihasmail meant reading the source, and a feature that quietly stopped working had nowhere to be contradicted.
FEATURES.md is that inventory, written from the code rather than the copy: the capability matrix and what each missing one removes, the search operators as the parser actually reads them, the Sieve tests and actions, every settings section and which of them follow the account, the shortcut set, the security posture, and the environment. Where a behaviour is odd it says why, because the reason is usually the stateless constraint.
It also records what the docs had not caught up with: single-occurrence edit and delete are built, and the id renumbering that made them hard is described where someone changing that code will find it.
jcoffey-dev