Add apt upgrade to SpoolBuddy install script

  Runs apt-get upgrade -y after installing system packages and the WiFi
  safeguard hook. Ensures the Pi is fully up to date before deploying
  SpoolBuddy, and the WiFi safeguard protects NM connections during
  the upgrade.

CHANGELOG.md

@@ -13,6 +13,7 @@ All notable changes to Bambuddy will be documented in this file.
 ### Improved
 - **Spool Notes in Assign Spool Modal** ([#793](https://github.com/maziggy/bambuddy/issues/793)) — Spool cards in the Assign Spool modal now show the spool's note as a hover tooltip, making it easier to identify spools by tracking IDs or other metadata stored in notes. Works with both internal inventory and Spoolman-synced spools. Requested by @LegionCanadian.
 - **WiFi Safeguard for SpoolBuddy Pi** — The install script now drops an APT hook (`/etc/apt/apt.conf.d/80-preserve-wifi`) that backs up NetworkManager WiFi connections before every `apt upgrade` and restores them if they get wiped. Prevents headless SpoolBuddy Pis from losing WiFi connectivity after Raspberry Pi OS package upgrades (observed with Bookworm kernel/raspi-config updates that clear `/etc/NetworkManager/system-connections/`).
+- **SpoolBuddy Install Script Now Upgrades System Packages** — The install script now runs `apt-get upgrade -y` after installing required packages and the WiFi safeguard. This ensures the Pi is fully up to date before SpoolBuddy is deployed, and the WiFi safeguard protects connectivity during the upgrade.
 
 ### Fixed
 - **Database Connection Pool Exhaustion on Large Printer Farms** — Users with 100+ printers connected simultaneously experienced `QueuePool limit of size 10 overflow 20 reached, connection timed out` errors. Increased the SQLAlchemy connection pool from 30 total (10 base + 20 overflow) to 220 (20 base + 200 overflow), and raised the SQLite busy_timeout from 5 to 15 seconds to reduce write contention under heavy concurrent MQTT updates.

spoolbuddy/install/install.sh

@@ -462,6 +462,10 @@ APTEOF
     success "WiFi safeguard installed (${hook_file})"
 }
 
+upgrade_system_packages() {
+    run_with_progress "Upgrading system packages" apt-get upgrade -y
+}
+
 # ─────────────────────────────────────────────────────────────────────────────
 # SpoolBuddy Installation
 # ─────────────────────────────────────────────────────────────────────────────
@@ -1335,6 +1339,7 @@ main() {
     # ── Step 2: System packages ───────────────────────────────────────────
     install_system_packages
     install_wifi_safeguard
+    upgrade_system_packages
     detect_python || error "Failed to install Python 3.10+"
     echo ""