feat(04-01): implement script_generator with install.ps1.j2 template

- Jinja2 Environment with FileSystemLoader, trim_blocks, lstrip_blocks
- render_install() with _duplex_map (LongEdge->TwoSidedLongEdge, ShortEdge->TwoSidedShortEdge)
- install.ps1.j2: WOW64 guard as first block (SCRPT-05)
- install.ps1.j2: SYSTEM/admin detection + UAC self-elevation (SCRPT-04)
- install.ps1.j2: pnputil two-step driver staging + Add-PrinterDriver (SCRPT-01)
- install.ps1.j2: idempotent port creation (Get-PrinterPort check)
- install.ps1.j2: idempotent printer creation (Get-Printer check)
- install.ps1.j2: Set-PrintConfiguration with duplex/color/paper/collate
- All 7 unit tests pass

imptune/templates/scripts/install.ps1.j2

@@ -0,0 +1,67 @@
+# Generated by ImpTune — Printer: {{ printer_name }}
+# Install command: powershell.exe -NoProfile -ExecutionPolicy Bypass -File "install.ps1"
+#
+# This script installs the printer "{{ printer_name }}" via Intune Win32 app deployment.
+# It must be launched with -File (not -Command) so $PSScriptRoot is populated.
+
+# ---------------------------------------------------------------------------
+# WOW64 Guard — relaunch in 64-bit PowerShell if running under WOW64 (Intune
+# runs Win32 app scripts in a 32-bit process; pnputil is 64-bit only).
+# This block MUST be the first executable code in the script.
+# ---------------------------------------------------------------------------
+if ($env:PROCESSOR_ARCHITECTURE -eq "x86" -and $env:PROCESSOR_ARCHITEW6432) {
+    $ps64 = "$env:WINDIR\SysNative\WindowsPowerShell\v1.0\powershell.exe"
+    & $ps64 -NoProfile -ExecutionPolicy Bypass -File "$PSCommandPath" @args
+    exit $LASTEXITCODE
+}
+
+# ---------------------------------------------------------------------------
+# SYSTEM vs User context detection + UAC self-elevation
+# Skip elevation when already running as SYSTEM (Intune MDM context).
+# ---------------------------------------------------------------------------
+$id       = [System.Security.Principal.WindowsIdentity]::GetCurrent()
+$isSystem = $id.IsSystem
+$isAdmin  = ([System.Security.Principal.WindowsPrincipal]$id).IsInRole(
+                [System.Security.Principal.WindowsBuiltInRole]::Administrator)
+
+if (-not $isSystem -and -not $isAdmin) {
+    Start-Process powershell.exe `
+        -Verb Runas `
+        -ArgumentList "-NoProfile -ExecutionPolicy Bypass -File `"$PSCommandPath`"" `
+        -Wait
+    exit $LASTEXITCODE
+}
+
+# ---------------------------------------------------------------------------
+# pnputil two-step driver staging
+# Step 1: Stage INF + all associated files into Windows Driver Store
+# Step 2: Install the named driver from the Driver Store
+# ---------------------------------------------------------------------------
+pnputil.exe /add-driver "$PSScriptRoot\drivers\{{ inf_filename }}" /install
+
+Add-PrinterDriver -Name "{{ driver_name }}"
+
+# ---------------------------------------------------------------------------
+# Idempotent port creation
+# ---------------------------------------------------------------------------
+if (-not (Get-PrinterPort -Name "{{ port_name }}" -ErrorAction SilentlyContinue)) {
+    Add-PrinterPort -Name "{{ port_name }}" -PrinterHostAddress "{{ ip_address }}"
+}
+
+# ---------------------------------------------------------------------------
+# Idempotent printer creation
+# ---------------------------------------------------------------------------
+if (-not (Get-Printer -Name "{{ printer_name }}" -ErrorAction SilentlyContinue)) {
+    Add-Printer -Name "{{ printer_name }}" `
+                -PortName "{{ port_name }}" `
+                -DriverName "{{ driver_name }}"
+}
+
+# ---------------------------------------------------------------------------
+# Configure print settings
+# ---------------------------------------------------------------------------
+Set-PrintConfiguration -PrinterName "{{ printer_name }}" `
+    -DuplexingMode {{ duplex_mode }} `
+    -Color ${{ color }} `
+    -PaperSize {{ paper_size }} `
+    -Collate ${{ collate }}