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>

Makefile

@@ -5,9 +5,9 @@
 #   make clean    — remove build artifacts
 #   make iso      — build the bootable ISO (requires Arch Linux + archiso)
 
-.PHONY: all wm deskbar launcher installer nebula clean install iso
+.PHONY: all wm deskbar launcher installer nebula orionpkg clean install iso
 
-all: wm deskbar launcher installer nebula
+all: wm deskbar launcher installer nebula orionpkg
 
 wm:
 	$(MAKE) -C wm
@@ -24,12 +24,16 @@ installer:
 nebula:
 	$(MAKE) -C nebula
 
+orionpkg:
+	$(MAKE) -C orionpkg
+
 clean:
 	$(MAKE) -C wm        clean
 	$(MAKE) -C deskbar   clean
 	$(MAKE) -C launcher  clean
 	$(MAKE) -C installer clean
 	$(MAKE) -C nebula    clean
+	$(MAKE) -C orionpkg  clean
 
 install: all
 	# binaries
@@ -38,6 +42,7 @@ install: all
 	install -Dm755 launcher/orionlauncher  /usr/local/bin/orionlauncher
 	install -Dm755 themes/orionwallpaper   /usr/local/bin/orionwallpaper
 	install -Dm755 nebula/nebula           /usr/local/bin/nebula
+	install -Dm755 orionpkg/orionpkg       /usr/local/bin/orionpkg
 	# GTK theme
 	mkdir -p /usr/share/themes
 	cp -r themes/OrionOS /usr/share/themes/