Label generator: gap, position and a back side

CHANGELOG.md

@@ -10,6 +10,37 @@ ADR-007 and ADR-002.
 
 ## [Unreleased]
 
+### Added
+
+- **The code generator can print a back side.** A badge card is two-sided and
+  the generator only ever emitted one page per card. The Back side section
+  turns on a second page per card carrying either the same code again, a fixed
+  block of text, its own per-row content (CSV `back` / `backlabel`), or
+  nothing. Page order is a choice, because the two kinds of printer want
+  opposite things: **interleaved** front-back-front-back for a duplex card
+  printer, **grouped** all-fronts-then-all-backs for a single-sided printer
+  that gets its stack flipped and reloaded. Getting that backwards prints
+  perfectly readable cards with the wrong back on every one, which is why the
+  order is pinned by tests rather than by looking at the preview.
+- **The gap between a code and its caption is its own control.** It was the
+  quiet zone doing double duty: closing up a caption meant shaving the clear
+  space a scanner needs, and the only way to get a code to scan was to push the
+  caption away from it. Quiet zone now means only the code's own margin; gap
+  means only the distance to the caption, and adds to the quiet zone rather
+  than eating into it. Every stock preset carries a gap that suits it.
+- **Contents can be positioned inside the label without moving the label.**
+  Align and Vertical place the code and caption block anywhere on the stock,
+  and Content X/Y nudge it from there. The existing X/Y nudge kept its
+  behaviour and is now labelled Media X/Y: it moves the whole printed area, for
+  a printer whose origin is off, which is a different problem from composing a
+  label.
+
+### Changed
+
+- CSV parsing and page building moved out of the generator component into
+  `plugins/tools/frontend/labelPages.js`, where the column contract and the
+  two-sided page order are covered by tests.
+
 ## [0.12.0] - 2026-08-20
 
 Printers become a property of the bay rather than of whoever last walked up to a