add config-sqlite and http-api adapters

SQLite config store: full ConfigRepository impl with JSON serialization
for mappings, layouts, data source configs. 12 integration tests.

HTTP API: Axum REST endpoints for widgets, data sources, layout, presets.
6 integration tests using tower::oneshot.

Port traits updated to return Send futures for Axum compatibility.

crates/adapters/config-sqlite/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "config-sqlite"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+domain.workspace = true
+sqlx.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+
+[dev-dependencies]
+tokio.workspace = true