chore: bump version to 0.1.9

sqlx migration release: rusqlite and tokio-postgres replaced with sqlx,
unified async connection pooling, optional runtime pattern for nested
tokio context safety.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: easel

Cargo.toml

@@ -15,7 +15,7 @@ members = [
 resolver = "2"
 
 [workspace.package]
-version = "0.1.8"
+version = "0.1.9"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/DocumentDrivenDX/axon"