ai-app/docs/DECISIONS.md

Decisions taken for Iris to review

Short list of design choices made by the design agent without asking, so they can be judged and reversed later. Detail lives in RUST.md (and IRIS.md for iris API changes); this file is only the summary. Newest first. Items marked DEFERRED are ones the agent chose not to decide alone.

2026-09-05

• Touch drag on a transcript row follows Android's own rule: a vertical drag pans the list immediately; a stationary press held 500 ms starts a text selection which further dragging extends; a horizontal drag while something is already selected extends that selection without the wait. One DragArbiter per list decides it (iris/src/sense.rs). Chosen over a "text layer always wins" or "list always wins" rule because either loses one of the two gestures a reader expects.
• E4's desktop shape is a new iris/desktop-app crate: a winit window holding transcript-ui's screen beside a session list, talking to a real ai-server through client-core. It enrols by pasting the same aiapp://enroll?… link a phone scans (client-core::config::EnrolledServer) and keeps it owner-only under $XDG_CONFIG_HOME/ai-app-desktop/. The pinned CA is a path given on the command line, not baked in. Chosen so the phone and desktop share one enrolment format and no second one is invented.
• Order of remaining work: finish the two in-flight pieces above, then the transcript screen's Android integration and the transcript-bench.sh comparison against Compose — the numbers the recommendation still lacks.
• DEFERRED — whether to commit to iris over Masonry for ai-app. Waits on the bench numbers above; RUST.md's recommendation says what the measurements must show.