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>

installer/orioninstall

@@ -18,7 +18,9 @@ if [[ "${1:-}" == "--gui" ]]; then
     HOSTNAME="${3:?missing hostname}"
     USERNAME="${4:?missing username}"
     PASSWORD="${5:?missing password}"
-    shift 5 2>/dev/null || true
+    TIMEZONE="${6:-UTC}"
+    KEYBOARD="${7:-us}"
+    shift 7 2>/dev/null || true
 fi
 
 # ── output helpers ────────────────────────────────────────────────────
@@ -193,8 +195,23 @@ sed -i 's/#en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen 2>/dev/null ||
 locale-gen
 echo "LANG=en_US.UTF-8" > /etc/locale.conf
 
+# Console keyboard layout
+echo "KEYMAP=${KEYBOARD:-us}" > /etc/vconsole.conf
+
+# X11 keyboard layout
+mkdir -p /etc/X11/xorg.conf.d
+cat > /etc/X11/xorg.conf.d/10-keyboard.conf <<KBEOF
+Section "InputClass"
+    Identifier "All Keyboards"
+    MatchIsKeyboard "on"
+    Driver "libinput"
+    Option "XkbLayout"  "${KEYBOARD:-us}"
+    Option "XkbOptions" "terminate:ctrl_alt_bksp"
+EndSection
+KBEOF
+
 # Timezone
-ln -sf /usr/share/zoneinfo/UTC /etc/localtime
+ln -sf "/usr/share/zoneinfo/${TIMEZONE:-UTC}" /etc/localtime
 hwclock --systohc 2>/dev/null || true
 
 # Remove live-only archiso package to prevent mkinitcpio confusion