Refactor first-boot process to introduce ordered execution and new one-shot scripts

Revise the first-boot script to implement a structured approach with 13 numbered steps, allowing for better control over the execution order. Introduce two new one-shot scripts: `01-set-rotation-once.sh` and `02-set-wallpaper-once.sh`, replacing the previous single script approach. Update documentation to reflect these changes, including the new configuration options for enabling/disabling steps and the revised file structure for one-shot scripts. Enhance the dashboard to display first-boot progress, improving user feedback during the initial setup.

emmc-provisioning/cloud-init/first-boot.conf

@@ -0,0 +1,60 @@
+# first-boot.conf.example
+# Copy to first-boot.conf and edit. Loaded by first-boot.sh from:
+#   - same directory as first-boot.sh, or
+#   - /tmp/first-boot.conf (when run via cloud-init), or
+#   - /etc/cm4-provisioning/first-boot.conf
+# Unset variables keep the script's built-in defaults.
+
+# --- File server & host ---
+# Base URL for first-boot assets (scripts, splash, configs). No trailing slash.
+FILE_SERVER="http://10.20.50.1:5000/files/first-boot"
+
+# Hostname set on the device.
+HOSTNAME="guard"
+
+# --- User ---
+# Login user (must exist; cloud-init user-data must create the same user).
+PI_USER="pi"
+
+# --- Paths (optional overrides) ---
+# First-boot log file.
+LOGFILE="/var/log/first-boot.log"
+
+# Plymouth custom theme directory.
+PLYMOUTH_DIR="/usr/share/plymouth/themes/custom"
+
+# Wallpaper path (splash.png is also copied here).
+WALLPAPER_PATH="/usr/share/rpd-wallpaper/splash.png"
+
+# --- Packages ---
+# Space-separated list of packages to install. Must include: git chromium wmctrl openssh-server
+# swaybg wlr-randr maliit-keyboard xinput-calibrator (for kiosk + labwc + touch).
+PACKAGES="git chromium wmctrl openssh-server swaybg wlr-randr maliit-keyboard xinput-calibrator"
+
+# --- Desktop & theme ---
+# LightDM session (rpd-labwc for Wayland + labwc).
+LIGHTDM_SESSION="rpd-labwc"
+
+# GTK dark theme name (e.g. PiXnoir; fallback is Adwaita-dark if missing).
+GTK_THEME_NAME="PiXnoir"
+
+# Wallpaper mode for pcmanfm (crop, stretch, fit, center, tile, screen, color).
+WALLPAPER_MODE="crop"
+
+# --- Display (reTerminal DM) ---
+# Kernel cmdline: DSI rotation. 90 = 90° clockwise; use 180 or 270 for other orientations.
+DSI_ROTATE="270"
+
+# Kernel cmdline: swiotlb size (for vc4-drm/DSI). Leave empty to skip.
+SWIOTLB_SIZE="65536"
+
+# --- reTerminal (Seeed) ---
+# Device passed to reTerminal.sh (reTerminal-DM for reTerminal DM).
+RETERMINAL_DEVICE="reTerminal-DM"
+
+# Seeed overlays repo (clone URL). Leave empty to skip driver install.
+RETERMINAL_REPO_URL="https://github.com/Seeed-Studio/seeed-linux-dtoverlays"
+
+# --- One-shots ---
+# Space-separated names of one-shot scripts (numbered = run order at first login). Leave empty for none.
+ONESHOT_SCRIPTS="01-set-rotation-once 02-set-wallpaper-once"