Recallyx 0.84

Add a one-command TestFlight upload script (#70)

Wraps the verified manual flow into scripts/testflight.sh: stamp
CFBundleVersion from the commit count (App Store Connect rejects
duplicates; the plist is trap-restored so the tree stays clean),
xcodegen, archive, and upload with automatic signing. --archive-only
builds without uploading. Friendly preflight errors for missing
xcodegen/Local.xcconfig/Xcode, and the "Failed to Use Accounts" upload
failure prints the actual fix (sign into Xcode, restart it once).

Verified end-to-end with --archive-only (stamped build 81, Info.plist
byte-identical after); the upload path is the same one used for today's
real TestFlight push.