Band Lineup Display, the backstage app itself

The Electron app that runs on the backstage PC: stage lineup photos with
mic/pack labels, packaged for Windows. It also carries the ProPresenter
Now/Next feature in two forms that share one engine — propresenter-core, where
every ProPresenter 7/20 quirk lives, and propresenter-app, the standalone
display it serves.

Until now this existed only on the production machine and as a read-only
snapshot inside the ProdDash repo. Source only: the 231 MB dist/ is build
output, and credentials, photos and processed images are written to the
Electron userData directory, never here. tmp/pp-mock.js stays — it is the
ProPresenter mock ProdDash's own CLAUDE.md tells people to run.

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

.gitignore

@@ -0,0 +1,13 @@
+# Band Lineup — source only. Runtime state (photos, PCO and ProPresenter
+# credentials, processed images) is written to the Electron userData
+# directory, never here.
+
+.DS_Store
+*.log
+
+node_modules/
+dist/
+logs/
+
+# tmp/ is kept on purpose: pp-mock.js is the ProPresenter mock the ProdDash
+# repo's CLAUDE.md tells people to run.