Add batch ULINE label printing for all asset types

A multi-select batch sheet at /print/asset-label-batch/<type> lays
selected assets onto ULINE label pages (6-up 3x3 or dense 72-up mini),
with code-type and encode toggles matching the single label, plus a
start-cell offset for partial sheets. Print Labels buttons on all five
asset list pages. The per-type config and encode resolution are
extracted to a shared print/assetLabel.js used by both the single and
batch views. Measuring-tool batches encode each tool inspection-
operation code (decode-verified 0615).

808 tests pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/views/machines/MachinesList.vue

@@ -2,6 +2,7 @@
   <div>
     <div class="page-header">
       <h2>Machines</h2>
+      <router-link to="/print/asset-label-batch/machine" class="btn btn-secondary" target="_blank">Print Labels</router-link>
       <router-link to="/machines/new" class="btn btn-primary">Add Machine</router-link>
     </div>