TASK-60: compositor half done, shell half specified

docs/tasks/60-the-multitasking-view.md

@@ -80,6 +80,49 @@ for the same shape and is worth reading before the shell half.
    composition, so `focus_border` suppresses itself while a window is owned by
    the transition and the card carries the chrome.
 
+### Compositor half: DONE 2026-08-07 (`souveraine-viewtop` `3c85397`)
+
+Gates green on archdev — 239 tests, `cargo fmt`, workspace clippy and
+`--features kms` clippy, all `-D warnings`. Not yet on the phone: needs a CI
+package and a session restart.
+
+- `crates/compositor/src/transition.rs` — the state. `begin(&[TransitionTarget])`
+  / `shift_to(0..=1)` / `commit(EndTarget)` / `cancel()` / `forget(id)`, seven
+  unit tests. Empty `begin` refused; `forget` on the last leg ends the flight;
+  `forget` is wired to surface destruction beside `navigation.forget`.
+- Wire: `OverviewBegin { to } / OverviewProgress { progress } / OverviewCommit
+  { target } / OverviewCancel`, plus `TransitionTarget` and `EndTarget`
+  (`home | overview | last_zone | zone{zone}`), all four in the verb table.
+- Geometry: `Viewtop::carried(window)` returns the lerped origin and scale, and
+  **`window_origin` and `window_extent` both consult it**, so the render and the
+  hit test inherit the carry with no call-site changes. Anchor is `(0,0)` on
+  purpose so `pose_origin`'s pivot term vanishes.
+- `focus_border` returns empty while a window is carried — the card owns the
+  frame.
+
+### Shell half: the next session, and it is well defined
+
+Rewrite the pill and `ZoneOverview` to drive the four verbs instead of posing
+windows and scaling cards independently.
+
+1. `ZoneOverview` computes each zone card's rect in panel coordinates. That rect
+   — not `0.6`, not an inset — is the `TransitionTarget` for the windows on that
+   zone.
+2. `SystemGestureRail.onPressed` → `overview_begin` with those rects.
+   `onPositionChanged` → `overview_progress`. Release → `overview_commit` with
+   the end target chosen from projected travel and dwell, or `overview_cancel`.
+3. **Delete** `ViewtopControl.poseActiveZone` / `clearPose` / `_posed` and
+   `GlobalStates.zonePullProgress`'s pose duties, and drop `zoneCard.scale`
+   entirely — the compositor is now carrying the real window onto that rect, so
+   a card that also scales is the second writer all over again. The card becomes
+   chrome: label, close control, and the neighbours either side.
+4. Tapping a card is `overview_commit { target: zone }` — which is what makes the
+   strand repro pass, because that path now releases like every other.
+
+Today's four shell commits (`57208c8`, `f699f57`, `452acea`, `72171ac`) are the
+two-writer design and step 3 deletes most of them. Kept on the phone meanwhile
+because the sizes at least agree.
+
 ### It has to be a verb, because she gives the tour
 
 Casey, 2026-08-07: there is a point where an agent is asked for a tour or a demo