feat(mobile): Add semantic versioning with standard-version

- Add standard-version for automated version bumping
- Create .versionrc with custom configuration for app.json
- Add version-updater.cjs script for Expo version syncing
- Add version bump scripts (release, release:patch, release:minor, release:major)
- Initialize CHANGELOG.md with v1.0.0 release notes
- Add iOS buildNumber and Android versionCode for app store releases
- Update .gitignore to allow CHANGELOG.md

This establishes proper engineering practices for version management.

mobile/scripts/version-updater.cjs

@@ -0,0 +1,39 @@
+/**
+ * Custom version updater for app.json
+ * Used by standard-version to update Expo app.json version fields
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+const APP_JSON_PATH = path.join(__dirname, '..', 'app.json');
+
+module.exports.readVersion = function (contents) {
+  const appJson = JSON.parse(contents);
+  return appJson.expo.version;
+};
+
+module.exports.writeVersion = function (contents, version) {
+  const appJson = JSON.parse(contents);
+
+  // Update expo.version
+  appJson.expo.version = version;
+
+  // Auto-increment build numbers for iOS and Android
+  const versionParts = version.split('.');
+  const buildNumber = parseInt(versionParts[0]) * 10000 +
+                      parseInt(versionParts[1]) * 100 +
+                      parseInt(versionParts[2]);
+
+  // Update iOS buildNumber
+  if (appJson.expo.ios) {
+    appJson.expo.ios.buildNumber = String(buildNumber);
+  }
+
+  // Update Android versionCode
+  if (appJson.expo.android) {
+    appJson.expo.android.versionCode = buildNumber;
+  }
+
+  return JSON.stringify(appJson, null, 2) + '\n';
+};