Add IndieAbout + IndieBackup, TestFlight release pipeline

IndieAbout: About section in iOS Settings and macOS About window; LICENSE
switched to the portfolio-standard ISC text (reflowed for in-app rendering).

IndieBackup: files-only backup/restore of the iCloud container documents
('.notesbackup' document type on both platforms), SwiftData cache rebuilt
via SyncEngine.rebuildCache() after restore, monitors suspended during the
file swap, onOpenURL import with pre-launch queueing.

Release pipeline: Scripts/release.sh (ios|mac|all) archives and uploads via
xcodebuild + ASC API key; platform-partitioned build numbers (iOS even,
macOS odd) since both targets share one bundle ID and build sequence.

.gitignore

@@ -3,3 +3,4 @@ DerivedData/
 *.xcodeproj
 .DS_Store
 xcuserdata/
+.env.release