fix(labels): replace incorrect ams_30x15 preset with correct AMS holder sizes (#1426)

Reporter — the same person who originally requested the labels
  feature in #809 — discovered that the ams_30x15 preset's 30x15 mm
  dimension didn't actually fit any variant of the MakerWorld AMS
  Filament Label Holder (model 752566) it advertised. Two new
  presets replace it:

  - ams_holder_74x33 (74 x 33 mm) matches the printable label STL
    bundled in the MakerWorld project
  - ams_holder_75x55 (75 x 55 mm) fits the cardstock-insert variant
    the reporter validated on bench

  Both cross the 20 mm height threshold so they land in the roomy
  layout branch — swatch on the left, QR on the right, multi-line
  text (brand, material, hex code, spool ID) in the middle. The
  old 30x15 mm preset couldn't fit a QR code; the new ones do.

  No DB migration: the preset name was never persisted. Callers
  scripting the old ams_30x15 value get a clean 422 at the route's
  Literal validator with the new valid values listed.

  i18n: replaced inventory.labels.templates.ams.{label,hint} with
  amsHolderSmall and amsHolderLarge across all 8 locales with real
  translations; parity guard cleaned of the stale English-fallback
  cognate entries. Parity holds at 4856 leaves per locale.

  Tests: backend label renderer + integration tests cover both new
  presets; LabelTemplatePickerModal test updated for the 6-button
  grid and the new template value in the API-call assertion.

static/index.html

@@ -26,7 +26,7 @@
 
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-    <script type="module" crossorigin src="/assets/index-D9JqDSB2.js"></script>
+    <script type="module" crossorigin src="/assets/index-Brndhbee.js"></script>
     <link rel="stylesheet" crossorigin href="/assets/index-KYwGxnG9.css">
   </head>
   <body>