[Light Switch] Switch desktop wallpapers with the Light/Dark mode (#42624)

I'm not sure how to set the AccentColor and ColorizationColor that is
consistent with the Settings App, and the same goes for switching
themes. If anyone has a solution, please let me know.


<img width="2010" height="1274" alt="2025-10-26 235808"
src="https://github.com/user-attachments/assets/b3eda45a-09f3-43bc-b87c-1b05bc308c24"
/>


- [x] Closes: #42436
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [x] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

---------

Co-authored-by: Jaylyn Barbee <51131738+Jaylyn-Barbee@users.noreply.github.com>

.github/actions/spell-check/expect.txt

@@ -456,6 +456,7 @@ DWMWINDOWATTRIBUTE
 DWMWINDOWMAXIMIZEDCHANGE
 DWORDLONG
 dworigin
+DWPOS
 dwrite
 dxgi
 eab
@@ -676,6 +677,7 @@ hicon
 HICONSM
 HIDEREADONLY
 HIDEWINDOW
+hif
 Hif
 HIMAGELIST
 himl
@@ -837,6 +839,7 @@ jpe
 jpnime
 Jsons
 jsonval
+jxl
 jxr
 keybd
 KEYBDDATA
@@ -1460,6 +1463,7 @@ recyclebin
 Redist
 Reencode
 REFCLSID
+REFGUID
 REFIID
 REGCLS
 regfile
@@ -1566,6 +1570,7 @@ SETBUDDYINT
 SETCONTEXT
 SETCURSEL
 setcursor
+SETDESKWALLPAPER
 SETFOCUS
 SETFOREGROUND
 SETHOTKEY
@@ -1654,6 +1659,7 @@ SKEXP
 SKIPOWNPROCESS
 sku
 SLGP
+slideshow
 sln
 slnf
 slnx
@@ -1890,6 +1896,7 @@ unwide
 unzoom
 UOffset
 UOI
+UPDATEINIFILE
 UPDATENOW
 UPDATEREGISTRY
 updown