feat(mobile): swipe to ask — bring the ask verb to the capture screen

[jayesh-keychain]

Goal

Bring the ask verb to mobile: a horizontal swipe switches the capture screen between capture mode (default, unchanged) and ask mode, where the user types a question and gets a grounded answer with citations.

Why now

Mobile currently implements only one of the four verbs. It calls exactly four endpoints — /auth/login, /memory/capture, /notifications, /notifications/register-token — and there is no reference to /memory/ask anywhere in apps/mobile. A user can put memories in from their phone but cannot ask anything of them; the "inform" screen is a notification feed, not a recall surface. Recall works end-to-end on the API and in Admin, so this is purely a missing mobile surface.

Scope — bigger than a gesture

This is not just mode-switching. It needs:

1. api.ask() in apps/mobile/src/lib/api.ts (the AskRequest/AskResponse contracts already exist in @thebrain/types).
2. An ask UI: query input, answer, citations, loading + honest-miss states.
3. The gesture + mode state.

How to do it

Axis matters. apps/mobile/app/index.tsx already drives BOTH hold-to-talk and slide-up-to-type from a single vertical Pan (see beginHold / slidingRef / dragY). The vertical axis is fully taken, so mode switching MUST be horizontal — a left/right swipe — or it will fight capture. Concretely this has already bitten us: adb vertical swipes during testing kept starting voice recordings instead of opening the composer.

• Add a horizontal Pan (or Gesture.Race with the existing one) with a clear activation threshold and activeOffsetX, so a mostly-vertical drag never switches modes and vice versa.
• Keep capture the default mode on every launch — asking is deliberate, capturing is reflexive. Do NOT persist the last mode.
• Reuse the existing composer input rather than building a second text surface.
• Ask goes through request() in src/lib/api.ts, so it inherits the 401 refresh-and-retry from fix(mobile): refresh the expired session instead of losing the capture #318 for free.
• Render citations from AskResponse.citations; an honest miss (citations: []) must read as "I don't have a memory about that", NOT as an error.

Out of scope

• Voice-driven ask (hold-to-talk stays capture-only).
• Multi-turn threads / sessionId — one-shot ask first.
• Any change to the recall pipeline or confidence bands.

Acceptance criteria

• App opens in capture mode every launch; existing hold-to-talk and slide-up-to-type behave exactly as before (no regression).
• A horizontal swipe switches to ask mode and back, with a visible mode indicator.
• A mostly-VERTICAL drag never switches mode; a mostly-HORIZONTAL drag never starts a recording or opens the text composer.
• Asking a question hits POST /memory/ask and renders the answer plus its citations.
• A grounded miss renders as an honest "no memory" state, not an error.
• A 401 mid-ask refreshes and retries once (inherited from fix(mobile): refresh the expired session instead of losing the capture #318) rather than dropping the question.
• Verified on a real emulator run, not just type-check — note that gesture surfaces are hard to drive via adb (a swipe registers as hold-to-talk), so this likely needs a manual pass or a test seam.

Notes

Blocked-ish on nothing, but see #319 (asymmetric query embedding): until that merges, ask on main returns "I don't have a memory about..." for most paraphrased questions, which would make this feature look broken when it isn't.

[jayesh-keychain]

Closing — superseded by a corrected plan, not abandoned.

What changed. This issue described a mode switch on the capture screen, but the implementation drifted toward a separate /ask route, and the direction is now explicit: capture and ask share ONE interface. There is no second screen. It also adds a requirement this issue never captured — the surface must show what the user asked, not just the answer.

Rather than rewrite the body and lose the trail, replacing with two properly-scoped issues.

What already landed and is NOT lost: api.ask() merged in #330 (cddbf8c) — transport only, inherits the #318 refresh-and-retry, and documents that a grounded miss is a 200 with empty citations, not an error. Both replacement issues build on it.

Replaced by the two issues linked below.

[jayesh-keychain]

Replaced by #331 (one surface for capture and ask) and #332 (show what was asked).