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/domain/src/ports/broadcast.rs

@@ -1,17 +1,18 @@
+use std::future::Future;
 use crate::entities::WidgetId;
 use crate::value_objects::{Layout, WidgetState};
 
 pub trait BroadcastPort {
     type Error;
 
-    async fn push_screen_update(
+    fn push_screen_update(
         &self,
         layout: &Layout,
         widgets: &[(WidgetId, WidgetState)],
-    ) -> Result<(), Self::Error>;
+    ) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
-    async fn push_data_update(
+    fn push_data_update(
         &self,
         updates: &[(WidgetId, WidgetState)],
-    ) -> Result<(), Self::Error>;
+    ) -> impl Future<Output = Result<(), Self::Error>> + Send;
 }

crates/domain/src/ports/config_repository.rs

@@ -1,3 +1,4 @@
+use std::future::Future;
 use crate::entities::{
     DataSource, DataSourceId, LayoutPreset, LayoutPresetId, WidgetConfig, WidgetId,
 };
@@ -6,21 +7,21 @@ use crate::value_objects::Layout;
 pub trait ConfigRepository {
     type Error;
 
-    async fn get_widget(&self, id: WidgetId) -> Result<Option<WidgetConfig>, Self::Error>;
-    async fn list_widgets(&self) -> Result<Vec<WidgetConfig>, Self::Error>;
-    async fn save_widget(&self, config: &WidgetConfig) -> Result<(), Self::Error>;
-    async fn delete_widget(&self, id: WidgetId) -> Result<(), Self::Error>;
+    fn get_widget(&self, id: WidgetId) -> impl Future<Output = Result<Option<WidgetConfig>, Self::Error>> + Send;
+    fn list_widgets(&self) -> impl Future<Output = Result<Vec<WidgetConfig>, Self::Error>> + Send;
+    fn save_widget(&self, config: &WidgetConfig) -> impl Future<Output = Result<(), Self::Error>> + Send;
+    fn delete_widget(&self, id: WidgetId) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
-    async fn get_data_source(&self, id: DataSourceId) -> Result<Option<DataSource>, Self::Error>;
-    async fn list_data_sources(&self) -> Result<Vec<DataSource>, Self::Error>;
-    async fn save_data_source(&self, source: &DataSource) -> Result<(), Self::Error>;
-    async fn delete_data_source(&self, id: DataSourceId) -> Result<(), Self::Error>;
+    fn get_data_source(&self, id: DataSourceId) -> impl Future<Output = Result<Option<DataSource>, Self::Error>> + Send;
+    fn list_data_sources(&self) -> impl Future<Output = Result<Vec<DataSource>, Self::Error>> + Send;
+    fn save_data_source(&self, source: &DataSource) -> impl Future<Output = Result<(), Self::Error>> + Send;
+    fn delete_data_source(&self, id: DataSourceId) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
-    async fn get_layout(&self) -> Result<Option<Layout>, Self::Error>;
-    async fn save_layout(&self, layout: &Layout) -> Result<(), Self::Error>;
+    fn get_layout(&self) -> impl Future<Output = Result<Option<Layout>, Self::Error>> + Send;
+    fn save_layout(&self, layout: &Layout) -> impl Future<Output = Result<(), Self::Error>> + Send;
 
-    async fn get_preset(&self, id: LayoutPresetId) -> Result<Option<LayoutPreset>, Self::Error>;
-    async fn list_presets(&self) -> Result<Vec<LayoutPreset>, Self::Error>;
-    async fn save_preset(&self, preset: &LayoutPreset) -> Result<(), Self::Error>;
-    async fn delete_preset(&self, id: LayoutPresetId) -> Result<(), Self::Error>;
+    fn get_preset(&self, id: LayoutPresetId) -> impl Future<Output = Result<Option<LayoutPreset>, Self::Error>> + Send;
+    fn list_presets(&self) -> impl Future<Output = Result<Vec<LayoutPreset>, Self::Error>> + Send;
+    fn save_preset(&self, preset: &LayoutPreset) -> impl Future<Output = Result<(), Self::Error>> + Send;
+    fn delete_preset(&self, id: LayoutPresetId) -> impl Future<Output = Result<(), Self::Error>> + Send;
 }

crates/domain/src/ports/data_source_port.rs

@@ -1,8 +1,9 @@
+use std::future::Future;
 use crate::entities::DataSource;
 use crate::value_objects::Value;
 
 pub trait DataSourcePort {
     type Error;
 
-    async fn poll(&self, source: &DataSource) -> Result<Value, Self::Error>;
+    fn poll(&self, source: &DataSource) -> impl Future<Output = Result<Value, Self::Error>> + Send;
 }

crates/domain/src/ports/event.rs

@@ -1,7 +1,8 @@
+use std::future::Future;
 use crate::events::DomainEvent;
 
 pub trait EventPublisher {
     type Error;
 
-    async fn publish(&self, event: DomainEvent) -> Result<(), Self::Error>;
+    fn publish(&self, event: DomainEvent) -> impl Future<Output = Result<(), Self::Error>> + Send;
 }