feat(09-03): add .ps1 script download routes and detail-page links

- Refactor install/uninstall/detect handlers into shared _*_response() helpers
- Add .ps1 route aliases: /scripts/install.ps1, /scripts/uninstall.ps1, /scripts/detect.ps1
- Add Scripts section to printer_detail.html inside {% if has_driver %} with 3 download links
- All 6 new tests green, full suite 106/106 passing

imptune/templates/printer_detail.html

@@ -45,6 +45,17 @@
     " x-text="copiedUninstall ? 'Copied!' : 'Copy'" class="secondary outline"></button>
   </div>
 
+  <h2>Scripts</h2>
+  <a href="/printers/{{ printer.id }}/scripts/install.ps1" role="button" class="secondary">
+    Download Install Script
+  </a>
+  <a href="/printers/{{ printer.id }}/scripts/uninstall.ps1" role="button" class="secondary">
+    Download Uninstall Script
+  </a>
+  <a href="/printers/{{ printer.id }}/scripts/detect.ps1" role="button" class="secondary">
+    Download Detect Script
+  </a>
+
   <h2>Export</h2>
   <a href="/printers/{{ printer.id }}/packages/ninja" role="button">Download NinjaRMM ZIP</a>
   <a href="/printers/{{ printer.id }}/packages/intunewin" role="button">Download .intunewin</a>