feat: add verified Linux install script

README.md

@@ -27,3 +27,13 @@ Windows cross-build:
 cargo install --locked cargo-xwin
 npm run bundle:windows
 ```
+
+## Linux install script
+
+Download and run the checked installer:
+
+```bash
+curl -fsSL https://fieldlens.arrowstack.dev/downloads/install.sh | sh
+```
+
+The script supports x86_64/amd64 Debian/Ubuntu-style systems, downloads the public `.deb`, verifies its SHA-256, then installs it with the system package manager.

downloads/SHA256SUMS

@@ -0,0 +1,2 @@
+2b8e73617c13603e88b37dd51da1b01093b2cb4022dcbe6ec2447982d771c5b8  fieldlens-print-linux-x64.deb
+82ac870a10591e05b144b61e3f5303a4e0fcb665668e8f02dfc93dca36c4a7ff  fieldlens-print-windows-x64-setup.exe

downloads/install.sh

@@ -0,0 +1,67 @@
+#!/usr/bin/env sh
+set -eu
+
+BASE_URL="${FIELDLENS_DOWNLOAD_BASE_URL:-https://git.arrowstack.dev/Admin/fieldlens-desktop/raw/branch/main/downloads}"
+PACKAGE="fieldlens-print-linux-x64.deb"
+EXPECTED_SHA256="2b8e73617c13603e88b37dd51da1b01093b2cb4022dcbe6ec2447982d771c5b8"
+
+say() {
+  printf '%s\n' "$*"
+}
+
+fail() {
+  printf 'FieldLens Print installer: %s\n' "$*" >&2
+  exit 1
+}
+
+case "$(uname -m)" in
+  x86_64|amd64) ;;
+  *) fail "this installer currently supports x86_64/amd64 Linux only" ;;
+esac
+
+command -v sha256sum >/dev/null 2>&1 || fail "sha256sum is required"
+
+tmpdir="$(mktemp -d 2>/dev/null || mktemp -d -t fieldlens-print)"
+trap 'rm -rf "$tmpdir"' EXIT HUP INT TERM
+package_path="$tmpdir/$PACKAGE"
+package_url="$BASE_URL/$PACKAGE"
+
+say "Downloading FieldLens Print..."
+
+if command -v curl >/dev/null 2>&1; then
+  curl -fL --retry 3 --retry-delay 1 -o "$package_path" "$package_url"
+elif command -v wget >/dev/null 2>&1; then
+  wget -O "$package_path" "$package_url"
+else
+  fail "curl or wget is required"
+fi
+
+actual_sha256="$(sha256sum "$package_path" | awk '{print $1}')"
+if [ "$actual_sha256" != "$EXPECTED_SHA256" ]; then
+  fail "checksum verification failed"
+fi
+
+say "Checksum verified."
+
+if [ "$(id -u)" -eq 0 ]; then
+  sudo_cmd=""
+elif command -v sudo >/dev/null 2>&1; then
+  sudo_cmd="sudo"
+else
+  fail "root access or sudo is required to install the package"
+fi
+
+if command -v apt-get >/dev/null 2>&1; then
+  say "Installing FieldLens Print..."
+  $sudo_cmd apt-get install -y "$package_path"
+elif command -v apt >/dev/null 2>&1; then
+  say "Installing FieldLens Print..."
+  $sudo_cmd apt install -y "$package_path"
+elif command -v dpkg >/dev/null 2>&1; then
+  say "Installing FieldLens Print..."
+  $sudo_cmd dpkg -i "$package_path"
+else
+  fail "this installer currently supports Debian/Ubuntu-style systems"
+fi
+
+say "FieldLens Print installed successfully."