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/http-api/src/lib.rs

@@ -0,0 +1,34 @@
+mod dto;
+mod routes;
+
+use std::sync::Arc;
+use axum::Router;
+use tower_http::cors::CorsLayer;
+use domain::{ConfigRepository, EventPublisher};
+
+pub struct AppState<C, E> {
+    pub config: Arc<C>,
+    pub events: Arc<E>,
+}
+
+impl<C, E> Clone for AppState<C, E> {
+    fn clone(&self) -> Self {
+        Self {
+            config: self.config.clone(),
+            events: self.events.clone(),
+        }
+    }
+}
+
+pub fn router<C, E>(state: AppState<C, E>) -> Router
+where
+    C: ConfigRepository + Send + Sync + 'static,
+    C::Error: std::fmt::Debug + Send,
+    E: EventPublisher + Send + Sync + 'static,
+    E::Error: std::fmt::Debug + Send,
+{
+    Router::new()
+        .nest("/api", routes::api_routes())
+        .layer(CorsLayer::permissive())
+        .with_state(state)
+}