Put the two collection actions in the collections panel

"Keep offline" and "Change library" were buttons in the library
header, in a row that is otherwise entirely library-wide. Both refer
to the tree instead.

"Keep offline" could only ever mean the scoped collection, while
sitting nowhere near the tree that says which that is — and while the
sidebar already offered the same question twice, on each row's tray
and on a held row. It now sits under the tree, in the panel whose
selection decides what it acts on, in the same place and shape the
trash already gives Restore and Empty. It stays a labelled control
rather than being dropped for the tray: a 26px row's tray is a small
thing to hit, and "Kept offline" spelt out for the collection you are
looking at is the discoverable version.

"Change library" was wedged between Sync and Rescan, two buttons that
act on the library you already have. Reading it as one of that group
is a way to lose a scan by aiming badly. It is now the last thing in
the panel, under the tree it replaces wholesale, behind a rule.

On a tablet both are one tap further away, behind the sidebar toggle
that leads the header. That is the panel a user is already in when
they scope the grid to a collection, so it is where they are when
either of these becomes the thing they want.

The grid keeps `pin-done`/`pin-total` and its progress bar: the
transfer is worth reporting wherever it was started from, including a
row the grid is not scoped to.

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:1208`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1182`</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:1217`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1191`</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:1225`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1199`</sub>
 
 ### Select a range
 
@@ -80,7 +80,7 @@ While selecting, a tap never opens. That is the whole point of the mode: one mea
 
 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:1286`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1260`</sub>
 
 ### Find photographs with two people in them
 
@@ -89,7 +89,7 @@ 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:1933`</sub>
+<sub>`ui/dr-ui/ui/library.slint:1902`</sub>
 
 ### Resize the thumbnails
 
@@ -98,7 +98,7 @@ 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:2559`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2528`</sub>
 
 ### File photographs in a collection
 
@@ -107,7 +107,7 @@ 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:2722`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2691`</sub>
 
 ### Open a photograph
 
@@ -116,7 +116,7 @@ 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:2977`</sub>
+<sub>`ui/dr-ui/ui/library.slint:2946`</sub>
 
 ### Rate a photograph without opening it
 
@@ -126,7 +126,7 @@ 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:3089`</sub>
+<sub>`ui/dr-ui/ui/library.slint:3058`</sub>
 
 ### Drop the selection but keep selecting
 
@@ -135,7 +135,7 @@ A star has to take the press without it also reaching the cell, or every rating
 
 Distinct from Done, which leaves the mode entirely. Clearing keeps it, so the next selection can start straight away.
 
-<sub>`ui/dr-ui/ui/library.slint:3744`</sub>
+<sub>`ui/dr-ui/ui/library.slint:3713`</sub>
 
 ### Select everything the grid is showing
 
@@ -144,4 +144,4 @@ Distinct from Done, which leaves the mode entirely. Clearing keeps it, so the ne
 
 A scoped grid of two hundred frames is two hundred taps otherwise, and "all of them, except those three" is a far more common shape than the taps it took to say it.
 
-<sub>`ui/dr-ui/ui/library.slint:3761`</sub>
+<sub>`ui/dr-ui/ui/library.slint:3730`</sub>