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>

BUILD_INSTRUCTIONS.md

@@ -0,0 +1,41 @@
+# Building Instructions
+
+## Quick Start
+
+1. **Install Dependencies**
+   ```bash
+   npm install
+   ```
+
+2. **Test the Application**
+   ```bash
+   npm start
+   ```
+   This will launch the app in development mode.
+
+3. **Build Windows Installer**
+   ```bash
+   npm run build:win
+   ```
+   This will create a Windows installer in the `dist` folder.
+
+## Building for Distribution
+
+After running `npm run build:win`, you'll find:
+- An installer executable in the `dist` folder (e.g., `Recurring Checklist Setup 1.0.0.exe`)
+- This installer can be copied to any Windows machine and run to install the application
+
+## Notes
+
+- The first build may take several minutes as it downloads Electron binaries
+- Each Windows machine will have its own independent checklist data
+- The app stores data locally using electron-store
+- No internet connection required after installation
+
+## Troubleshooting
+
+If you encounter issues building:
+1. Make sure Node.js is installed (version 14 or higher recommended)
+2. Try deleting `node_modules` and running `npm install` again
+3. On Windows, you may need to install build tools: `npm install --global windows-build-tools`
+