v1.40.0
Late-bound connection refs in sync profiles. Re-auth no longer breaks profiles.
```json
"connection": { "platform": "gmail" } // single account
"connection": { "platform": "gmail", "tag": "work@example.com" } // multi-account
```
Resolution runs at sync test/run time. After `one add gmail` (re-auth), the next sync picks up the fresh key automatically — no manual edits across profiles.
Backwards compatible: literal `connectionKey` still works. Built-in profiles migrated.
Closes #114. Partial fix for #113 (closed). Flow engine support to follow.