Add orionpkg (package manager GUI) + installer locale step

orionpkg/orionpkg.c (~500 lines, native Xlib/Xft):
- Launches with checkupdates (pacman-contrib) to list pending upgrades
- ST_CHECKING: animated spinner while querying
- ST_UPDATES: scrollable package list with name / old ver → new ver columns
- ST_UPDATING: pkexec pacman -Syu in background, live log output,
  progress bar estimated from pacman's (N/M) counters
- ST_DONE / ST_ERROR: success or failure screen
- Refresh (r key), scroll (mouse wheel / arrow keys), Close (Esc/q)
- pacman-contrib added to ISO packages

Installer: add STEP_LOCALE (timezone + keyboard layout):
- Inserted between STEP_DISK and STEP_USER
- Timezone pane: searchable filter input + scrollable list of 37 zones
- Keyboard pane: 20 common layouts with code + description
- Timezone and keyboard passed as args 6/7 to orioninstall
- orioninstall: sets /etc/vconsole.conf and X11 xorg.conf.d keyboard
  config from args; uses selected timezone for localtime symlink

Also:
- Right-click menu: "Software Updates" → orionpkg
- Root Makefile: orionpkg target + install rule
- ISO: orionpkg binary installed, permissions map, gitignore

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/docker/entrypoint.sh

@@ -87,6 +87,7 @@ xclip
 scrot
 parcellite
 papirus-icon-theme
+pacman-contrib
 zip
 unzip
 p7zip
@@ -231,6 +232,7 @@ install -m755 "$SRC/deskbar/oriondeskbar"    "$AIROOTFS/usr/local/bin/oriondeskb
 install -m755 "$SRC/launcher/orionlauncher"  "$AIROOTFS/usr/local/bin/orionlauncher"
 install -m755 "$SRC/themes/orionwallpaper"      "$AIROOTFS/usr/local/bin/orionwallpaper"
 install -m755 "$SRC/nebula/nebula"              "$AIROOTFS/usr/local/bin/nebula"
+install -m755 "$SRC/orionpkg/orionpkg"          "$AIROOTFS/usr/local/bin/orionpkg"
 install -m755 "$SRC/installer/orioninstall"        "$AIROOTFS/usr/local/bin/orioninstall"
 # GUI installer (compiled binary; falls back gracefully if not built)
 if [[ -f "$SRC/installer/orioninstall-gui" ]]; then
@@ -690,6 +692,7 @@ file_permissions=(
   ["/usr/local/bin/orionlauncher"]="0:0:755"
   ["/usr/local/bin/orionwallpaper"]="0:0:755"
   ["/usr/local/bin/nebula"]="0:0:755"
+  ["/usr/local/bin/orionpkg"]="0:0:755"
   ["/usr/local/bin/orioninstall"]="0:0:755"
 )
 PROFILEDEF