Switchman 1.6.1

Mail document links open correctly, and failed short-link and iCloud sync retries are gentler.

• Mail document links. Mail sometimes hands the system a document-relative link as x-webdoc://<document-id>/www.example.com/path. Switchman now registers for that scheme and recovers the web address only when the first path segment looks like a hostname; anything else is left untouched for the ordinary unsupported-scheme guard to reject.
• A broken short-link service no longer holds the picker hostage. A shortener that fails is treated as an ordinary URL for the rest of that launch; the next launch gives it a fresh chance.
• iCloud sync backs off after a failure. After a CloudKit error, retries stretch to 30, 60, 120, 240 and 480 seconds, then a ten-minute ceiling, instead of hammering every five seconds.