[valicm]

• macOS notarization is its own job. The build no longer notarizes the DMG; it passes the DMG on to a new macos-notarize job. That job notarizes it, staples the ticket (up to five tries, since Apple's ticket service drops connections), checks it with codesign, stapler and Gatekeeper, and replaces the release's DMG. If it fails, re-running it takes a minute or two instead of a full macOS build.
• Windows signing retries. Each file is signed up to four times, 20 seconds apart, because Microsoft's timestamp server doesn't always answer.
• TestFlight upload retries (scripts/upload-ios.py):
  • Requests that are safe to repeat are retried after 5, 15, 30 and 60 seconds when the connection drops, times out or gets a server error. Upload parts are retried too.
  • Requests that would start a new upload are never repeated.
  • The final upload confirmation now waits up to 5 minutes.
  • A build that App Store Connect already has counts as uploaded, so re-running the job is always safe.
• Version 0.2.1 on develop (Android version code 20100), so dev builds number past the release. Cargo.lock only changes our own crates' versions.
• Docs: RELEASING.md and docs/development.md describe the new job layout and the retries.