Bring the checklist app under version control

The project has lived only as a folder on the Mac Studio and, briefly, as a
transfer tarball. This is the first commit: the Express server and its web
front end, the Capacitor iOS and Android wrappers, and the release and backup
scripts.

The repo is the source, not a backup of the machine. Left out on purpose, by
the .gitignore files that were already in the tree: node_modules, build output,
mobile/www (regenerated from server/public on every build), and server/data,
which holds the live checklists and belongs on the NAS rather than in git.

Every credential is excluded too — server/.env, the Play upload keystore and
its properties file, the App Store Connect key and ios-signing.config. The one
secret that was not in an ignored file was the NAS SSH password, hard-coded in
build-deploy.sh and grepped back out of it by backup-to-drive.sh. Both now read
it from the login keychain (service checklist-nas, account Christian), falling
back to NAS_PASS in the environment, so rotating it is one keychain entry
rather than a history rewrite.

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

mobile/release.config.json

@@ -0,0 +1,12 @@
+{
+  "_comment": "Single source of truth for what the store builds point at and how they're numbered. release.sh bumps the three numbers; everything else is hand-edited and rarely changes.",
+  "apiBase": "https://check.watersmedia.org",
+  "version": "1.0.0",
+  "iosBuild": 8,
+  "androidVersionCode": 6,
+  "_versionNotes": [
+    "version           — the marketing version users see, shared by both stores (CFBundleShortVersionString / versionName).",
+    "iosBuild          — CFBundleVersion. Must strictly increase for every binary uploaded to App Store Connect, even a re-upload of the same version.",
+    "androidVersionCode— Play's versionCode. Must strictly increase for every AAB uploaded. Play NEVER lets a code be reused, even after deleting the release."
+  ]
+}