tanin-icons: accent-reactive folder icon theme (replaces Papirus)

New package packaging/tanin-icons/ generating 5 thin themes Tanin-<accent>
that inherit Adwaita and recolour only the folder/place ramp to the muted
Fuji accent (HSL shift keeping per-stop lightness; 16px rasterised so the
size-exact inherited blue PNG can't win).

- style.py: _set_gsettings now also sets icon-theme=Tanin-<accent_key> so
  folders recolour live with the accent.
- desktop.py: hide Tanin-* from the manual icon picker (accent-driven, a
  manual pick would be overridden on the next accent change).
- panel.py: pin-add icon hint Papirus -> Adwaita.
- build/finish-tanin-repo.sh: tanin-icons in OWN_SIMPLE; AUR rebuilds add
  librewolf-bin, arch-update, timeshift-autosnap, xdg-terminal-exec, paru.
- camel.toml: icon_theme=Tanin-<accent>, icons=[adwaita], tanin-icons own
  package + the new rebuilt_aur entries.

Deliberately excludes unrelated in-flight work (calendar/gtklock/
online-accounts/overview-backdrop) still uncommitted in the tree.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packaging/build-tanin-repo.sh

@@ -15,9 +15,11 @@ OUT="${TANIN_REPO_DIR:-$HOME/projects/tanin-repo}"
 DB="$OUT/tanin.db.tar.zst"
 mkdir -p "$OUT"
 
-OWN_SIMPLE=(tanin-greet tanin-libadwaita tanin-setup tanin-eww tanin-desktop)
+# tanin-icons builds from the installed Adwaita theme -> needs librsvg + python.
+OWN_SIMPLE=(tanin-greet tanin-libadwaita tanin-setup tanin-eww tanin-icons tanin-desktop)
 OWN_BUILD=(taninux)
-AUR_REBUILD=(eww-git tiramisu-git waypaper calamares)
+AUR_REBUILD=(eww-git tiramisu-git waypaper calamares librewolf-bin
+             arch-update timeshift-autosnap xdg-terminal-exec paru)
 
 build() {
   local p="$1"