chore(v1.1.7): version bumps + CHANGELOG

- workspace 1.1.6 → 1.1.7
- SDK schema 1.7 → 1.8 (SecretsService, EmailService, TriggerEvent::Email)
- dashboard 0.12.0 → 0.13.0
- CHANGELOG entry: secrets, outbound email, inbound email, retroactive
  dead_letter fix note, realtime-key encryption migration (+ v1.1.8 drop)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -13,7 +13,7 @@ members = [
 ]
 
 [workspace.package]
-version = "1.1.6"
+version = "1.1.7"
 edition = "2021"
 rust-version = "1.92"
 license = "MIT OR Apache-2.0"