Put the people filter where the filters are

Narrowing the grid to two people at once has worked since people became
a selector term, and it was effectively unreachable. The only control
that could add a second person lived on the People screen, behind
selecting them there, and it appeared only once the grid was already
narrowed to somebody — so "photographs with both of them" needed a
two-screen round trip the user had to guess at.

A filter belongs on the filter bar. A "People" chip there opens a tray of
everyone the library knows; tapping a name adds or removes them, and the
any/all chip beside it — already there, and already the thing nobody
found — now has something to sit next to that explains it. The caption
leads the row so a pair of chips means something before either is
pressed.

The tray is a strip under the bar rather than a popup, the way the
develop column's film picker is: the view scrolls as one, so an inline
strip is taller content and not a second overlay to dismiss. It scrolls
horizontally for the same hard reason the bar above it does — a layout
cannot be narrower than its children's minimums, and forty people would
otherwise set the minimum width of the whole view.

The roster is built on open, not kept in step: indexing and regrouping
change who exists, and a list cached at startup would be stale for
exactly the user who has just been naming people. Named first, then by
how much of them the library holds — the catalog orders by face count
alone, which puts a dozen unnamed strangers ahead of the two people the
user actually cares about.

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

ui/dr-ui/ui/app.slint

@@ -606,6 +606,10 @@ export component AppWindow inherits Window {
     in property <bool> library-filter-people-all: false;
     callback library-filter-person-cleared(int);
     callback library-filter-people-mode-toggled();
+    /// Everyone the library knows, for the filter bar's people tray.
+    in property <[PersonChip]> library-people;
+    callback library-people-listed();
+    callback library-filter-person-toggled(int);
     in property <int> library-filter-min-rating: 0;
     in property <bool> library-filter-unjudged: false;
     in property <int> library-filter-flag: 0;
@@ -1568,6 +1572,7 @@ in property <bool> panel-visible: true;
 
                     filter-people: root.library-filter-people;
                     filter-people-all: root.library-filter-people-all;
+                    people: root.library-people;
                     filter-min-rating: root.library-filter-min-rating;
                     filter-unjudged: root.library-filter-unjudged;
                     filter-flag: root.library-filter-flag;
@@ -1600,6 +1605,8 @@ in property <bool> panel-visible: true;
                     filter-flag-changed(f) => { root.library-filter-flag-changed(f); }
                     filter-person-cleared(id) => { root.library-filter-person-cleared(id); }
                     filter-people-mode-toggled() => { root.library-filter-people-mode-toggled(); }
+                    people-listed() => { root.library-people-listed(); }
+                    filter-person-toggled(id) => { root.library-filter-person-toggled(id); }
                 }
             }
         }