When the SDK sends identify calls with identical payloads (common on
every page load), `save!` fires even though no attributes changed. While
Rails skips the actual UPDATE SQL, it still opens a transaction, runs
all callbacks (including validation queries like `Contact Exists?`), and
triggers `after_commit` hooks — all for a no-op.
This adds a `changed?` guard before `save!` to skip it entirely when no
attributes have actually changed.
**How to test**
- Trigger an identify call via the SDK with a contact's existing
attributes (same name, email, custom_attributes, etc.)
- The contact should not fire a save (no transaction, no callbacks)
- Trigger an identify call with a changed attribute — save should work
normally
**What changed**
- `ContactIdentifyAction#update_contact`: guard `save!` with `changed?`
check
- Added specs to verify `save!` is skipped for unchanged params and
avatar job still enqueues independently