Take the photo roll's grab band off the buttons that end a mode

"Done Cropping", "Done Repairing", "Done Masking" and "Fit" float over
the foot of the canvas. So does the photo roll's swipe handler, and a
gesture handler is not a layout box — it is an input surface. A press
inside one is delayed, then offered to that handler's own children and
to nothing else: `input_event_filter_before_children` returns
`DelayForwarding`, which aborts the hit-test traversal outright, and the
replay afterwards visits only the handler's subtree. Everything behind
it is never asked, hover included.

The band was `strip-height + reach` — 136px along the bottom — whether
the roll was out or away. So the button that ends a mode was drawn, was
lit, and did nothing for as long as a library was open, which is the
whole time anybody is developing from one. The tool rail kept working
because it is a sibling of the canvas rather than behind the roll, which
is exactly why this looked like two dead buttons rather than a dead
region.

The band now goes where the roll goes. The handler carries the strip
instead of standing still while the strip animates inside it: closed,
only `reach` is on screen and the rest hangs below the window where
nothing can press it; open, it still covers the thumbnails, which is
what lets a swipe down anywhere across them put the roll away. The
180ms travel moved from the strip onto the handler, so the drawn
positions in both states are what they were.

The controls are then positioned against that band rather than against
the bottom of the canvas, and ride up with the strip when it comes out.
Reordering them in front of the roll would have been the other fix, and
it is the wrong one — the band would become the thing that cannot be
reached, and a gesture nobody can start is worse than a button with a
second way out.

`roll-strip` and `roll-reach` are tokens now, because two files have to
agree on where that band is for either of them to keep out of it.

The bottom of the photograph comes back with it: the crop's lower
handles and a repair placed near the bottom edge were inside the same
136px and had the same fault.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/gestures.md

@@ -54,7 +54,7 @@ The right match confidence is a property of your library, not of the model. "Wha
 
 Touch has no ctrl, so without a mode there is no way to select a second photograph — the first tap would open it. The hold is the fast way in and the button is the one that can be found.
 
-<sub>`ui/dr-ui/ui/library.slint:1184`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1217`</sub>
 
 ### Add or remove one photograph
 
@@ -63,7 +63,7 @@ Touch has no ctrl, so without a mode there is no way to select a second photogra
 
 While selecting, a tap never opens. That is the whole point of the mode: one meaning per gesture at a time. Press Done to get tap-to-open back.
 
-<sub>`ui/dr-ui/ui/library.slint:1193`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1226`</sub>
 
 ### Leave selecting
 
@@ -71,7 +71,7 @@ While selecting, a tap never opens. That is the whole point of the mode: one mea
 - **Pointer** — Press Done in the header
 - **Keyboard** — Escape
 
-<sub>`ui/dr-ui/ui/library.slint:1201`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1234`</sub>
 
 ### Pick a photograph up to drag it
 
@@ -80,7 +80,7 @@ While selecting, a tap never opens. That is the whole point of the mode: one mea
 
 A finger on a photograph might be starting a scroll, and for the first half-second the grid assumes it is. Holding says otherwise, and the ring is the grid saying it heard — from there the drag cannot be lost to a scroll. A mouse never waits: the cursor is precise enough that a sideways drag is unambiguous from the first pixel.
 
-<sub>`ui/dr-ui/ui/library.slint:1231`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1264`</sub>
 
 ### Select a range
 
@@ -89,7 +89,7 @@ A finger on a photograph might be starting a scroll, and for the first half-seco
 
 This replaced a double tap, which had no visible state and could take forty photographs by accident. The run is resolved by the catalog rather than by what is on screen, so the grid can scroll between the two taps — the ranges that hurt on a tablet are longer than a screenful, which is exactly where a finger sweep runs out.
 
-<sub>`ui/dr-ui/ui/library.slint:1296`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1329`</sub>
 
 ### Find photographs with two people in them
 
@@ -98,7 +98,7 @@ This replaced a double tap, which had no visible state and could take forty phot
 
 "Any of them" is a union and "all of them" is an intersection. The tray is where both terms and the choice between them live, because a filter belongs on the filter bar.
 
-<sub>`ui/dr-ui/ui/library.slint:1978`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2011`</sub>
 
 ### Resize the thumbnails
 
@@ -107,7 +107,7 @@ This replaced a double tap, which had no visible state and could take forty phot
 
 There is no wheel on a tablet, so without the pinch the cell size could only be changed by a control a finger cannot reach.
 
-<sub>`ui/dr-ui/ui/library.slint:2620`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2664`</sub>
 
 ### File photographs in a collection
 
@@ -116,7 +116,7 @@ There is no wheel on a tablet, so without the pinch the cell size could only be
 
 The selection is what the drag carries, which is why selecting several is worth the mode: forty photographs file in one gesture.
 
-<sub>`ui/dr-ui/ui/library.slint:2783`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2827`</sub>
 
 ### Open a photograph
 
@@ -125,7 +125,7 @@ The selection is what the drag carries, which is why selecting several is worth
 
 A tap opens; a tap that *moved* does not. Travel is what separates a deliberate tap from a hand brushing past, and it is the only thing that does: the two are the same length. An earlier version required the finger to dwell 120 ms instead, and that rejected ordinary taps — a real tap is often quicker than a brush.
 
-<sub>`ui/dr-ui/ui/library.slint:3051`</sub>
+<sub>`ui/dr-ui/ui/library.slint:3095`</sub>
 
 ### Rate a photograph without opening it
 
@@ -135,7 +135,7 @@ A tap opens; a tap that *moved* does not. Travel is what separates a deliberate
 
 A star has to take the press without it also reaching the cell, or every rating throws the user into develop.
 
-<sub>`ui/dr-ui/ui/library.slint:3171`</sub>
+<sub>`ui/dr-ui/ui/library.slint:3215`</sub>
 
 ### Drop the selection but keep selecting