feat(gui): slideshow in the photo viewer

A new top-bar button, or F5, plays the loaded photos as a slideshow: it goes
fullscreen, hides the controls and moves on every five seconds. A video plays
to its end first, and the slideshow waits for each photo to load before it
starts counting. Stepping by hand restarts the count. Escape stops the
slideshow instead of closing the viewer, and fullscreen is left only if the
slideshow entered it. The slideshow ends on the last photo of the timeline.

po/nl.po

@@ -5,7 +5,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: proton-drive-linux 2.1.0\n"
 "Report-Msgid-Bugs-To: https://github.com/narrrl/proton-drive-linux/issues\n"
-"POT-Creation-Date: 2026-09-28 00:13+0200\n"
+"POT-Creation-Date: 2026-09-28 00:14+0200\n"
 "PO-Revision-Date: 2026-09-23 12:00+0200\n"
 "Last-Translator: Proton Drive for Linux contributors\n"
 "Language-Team: Dutch\n"
@@ -400,7 +400,7 @@ msgstr "Kon activiteit niet lezen"
 #: crates/pdfs-gui/src/app/pages/activity.rs:275
 #: crates/pdfs-gui/src/app/pages/browser.rs:2880
 #: crates/pdfs-gui/src/app/pages/browser.rs:3066
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:292
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:310
 #: crates/pdfs-gui/src/app/pages/photos.rs:3077
 #: crates/pdfs-gui/src/app/pages/shared_by_me.rs:139
 #: crates/pdfs-gui/src/app/pages/trash.rs:320
@@ -731,7 +731,7 @@ msgstr "Kon het album niet aanmaken"
 #: crates/pdfs-gui/src/app/pages/locations.rs:739
 #: crates/pdfs-gui/src/app/pages/locations.rs:1090
 #: crates/pdfs-gui/src/app/pages/locations.rs:1109
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1297
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1424
 #: crates/pdfs-gui/src/app/pages/photos.rs:1234
 #: crates/pdfs-gui/src/app/pages/photos.rs:1947
 #: crates/pdfs-gui/src/app/pages/photos.rs:2912
@@ -1088,7 +1088,7 @@ msgid "Location"
 msgstr "Locatie"
 
 #: crates/pdfs-gui/src/app/pages/browser.rs:1256
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:998
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1110
 msgid "Open With…"
 msgstr "Openen met…"
 
@@ -1126,7 +1126,7 @@ msgid "Versions…"
 msgstr "Versies…"
 
 #: crates/pdfs-gui/src/app/pages/browser.rs:1302
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1032
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1145
 msgid "Details"
 msgstr "Details"
 
@@ -2387,171 +2387,175 @@ msgid "Sign Out"
 msgstr "Afmelden"
 
 #. Translators: tooltip of the button that switches to another file of the same photo; {name} is a file name.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:182
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:194
 #, rust-format
 msgid "Show {name}"
 msgstr "{name} tonen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:185
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:197
 msgid "Show the raw file"
 msgstr "Het RAW-bestand tonen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:186
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:198
 msgid "Show the video"
 msgstr "De video tonen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:187
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:199
 msgid "Show the photo"
 msgstr "De foto tonen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:288
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:306
 msgid "Couldn't render this photo."
 msgstr "Kon deze foto niet weergeven."
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:293
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:311
 msgid "Couldn't reach Proton Drive."
 msgstr "Kon Proton Drive niet bereiken."
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:345
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:449
 msgid "Reading photo details…"
 msgstr "Fotodetails lezen…"
 
 #. Translators: label of a photo's file size in the details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:362
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:466
 msgctxt "property"
 msgid "Size"
 msgstr "Grootte"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:368
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:472
 msgid "This photo carries no metadata."
 msgstr "Deze foto bevat geen metadata."
 
 #. Translators: a photo's pixel dimensions, such as "4032 × 3024".
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:441
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:545
 #, rust-format
 msgid "{width} × {height}"
 msgstr "{width} × {height}"
 
 #. Translators: label of a photo's pixel dimensions in the details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:444
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:548
 msgid "Dimensions"
 msgstr "Afmetingen"
 
 #. Translators: label of when a photo was taken, in the details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:448
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:552
 msgctxt "photo property"
 msgid "Taken"
 msgstr "Genomen"
 
 #. Translators: label of the camera model in a photo's details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:453
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:557
 msgid "Camera"
 msgstr "Camera"
 
 #. Translators: label of the lens model in a photo's details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:457
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:561
 msgid "Lens"
 msgstr "Lens"
 
 #. Translators: a photo's ISO sensitivity, such as "ISO 400".
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:472
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:576
 #, rust-format
 msgid "ISO {value}"
 msgstr "ISO {value}"
 
 #. Translators: label of aperture, shutter speed, ISO and focal length in a photo's details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:484
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:588
 msgid "Exposure"
 msgstr "Belichting"
 
 #. Translators: label of where a photo was taken, in the details panel.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:492
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:596
 msgctxt "photo property"
 msgid "Location"
 msgstr "Locatie"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:495
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:599
 #, rust-format
 msgid "{latitude}, {longitude}"
 msgstr "{latitude}, {longitude}"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:685
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:789
 msgid "Save a Copy"
 msgstr "Een kopie opslaan"
 
 #. Translators: {name} is the saved file's name.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:706
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:810
 #, rust-format
 msgid "Saved “{name}”"
 msgstr "“{name}” opgeslagen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:708
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:711
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:812
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:815
 msgid "Couldn't save the copy"
 msgstr "Kon de kopie niet opslaan"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:712
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:816
 msgid "The copy was interrupted."
 msgstr "Het kopiëren is onderbroken."
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:839
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:844
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:943
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:948
 #, rust-format
 msgid "{position} of {total}"
 msgstr "{position} van {total}"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:849
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:953
 #, rust-format
 msgid "{position} of {loaded}+"
 msgstr "{position} van {loaded}+"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:877
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:981
 msgid "Photo"
 msgstr "Foto"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:924
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1028
 msgid "Previous (←)"
 msgstr "Vorige (←)"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:938
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1042
 msgid "Next (→)"
 msgstr "Volgende (→)"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:976
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1080
 msgid "Details (i)"
 msgstr "Details (i)"
 
 #. Translators: tooltip of the star button that marks a photo as a favorite.
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:985
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1089
 msgctxt "verb"
 msgid "Favorite"
 msgstr "Favoriet maken"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:993
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1097
+msgid "Slideshow (F5)"
+msgstr "Diavoorstelling (F5)"
+
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1105
 msgid "Other files of this photo"
 msgstr "Andere bestanden van deze foto"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:996
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1108
 msgid "Save a Copy…"
 msgstr "Een kopie opslaan…"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:997
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1109
 msgid "Move to Trash (Delete)"
 msgstr "Naar prullenbak verplaatsen (Delete)"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:999
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1111
 msgid "Close (Esc)"
 msgstr "Sluiten (Esc)"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1022
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1135
 msgid "Show on map"
 msgstr "Tonen op kaart"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1040
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1153
 msgid "Hide details"
 msgstr "Details verbergen"
 
-#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1302
+#: crates/pdfs-gui/src/app/pages/photo_viewer.rs:1429
 #: crates/pdfs-gui/src/app/pages/photos.rs:2907
 #: crates/pdfs-gui/src/app/pages/photos.rs:2911
 msgid "Couldn't change the favorite"