presentation: HTTP server crate w/ handlers, routes, background tasks

Axum binary that wires all clean-arch crates together:
- AppState holds pre-built Deps structs (auth, channels, schedule, library, etc.)
- JWT extractors (CurrentUser, AdminUser, OptionalCurrentUser)
- Handlers delegate to application use cases, map to api-types DTOs
- Routes: auth, channels, schedule, library, admin, providers, config, iptv
- Background: auto-scheduler, broadcast poller, webhook consumer, library sync
- Factory builds everything from Config + DbPool
- SimpleProviderRegistry impl of IProviderRegistry trait
- NoopMediaProvider fallback

crates/presentation/src/handlers/providers.rs

@@ -0,0 +1,72 @@
+//! Provider configuration CRUD handlers.
+
+use axum::Json;
+use axum::extract::{Path, State};
+
+use api_types::{ProviderConfigRequest, ProviderConfigResponse};
+use application::providers::{
+    DeleteProviderCommand, GetProviderQuery, ListProvidersQuery, UpsertProviderCommand,
+};
+
+use crate::errors::ApiError;
+use crate::extractors::AdminUser;
+use crate::state::AppState;
+
+/// GET /admin/providers
+pub async fn list_providers(
+    State(state): State<AppState>,
+    AdminUser(_user): AdminUser,
+) -> Result<Json<Vec<ProviderConfigResponse>>, ApiError> {
+    let providers =
+        application::providers::list::execute(&state.provider_deps, ListProvidersQuery).await?;
+    Ok(Json(
+        providers
+            .into_iter()
+            .map(ProviderConfigResponse::from)
+            .collect(),
+    ))
+}
+
+/// GET /admin/providers/:id
+pub async fn get_provider(
+    State(state): State<AppState>,
+    AdminUser(_user): AdminUser,
+    Path(id): Path<String>,
+) -> Result<Json<ProviderConfigResponse>, ApiError> {
+    let query = GetProviderQuery { id: id.clone() };
+    let provider = application::providers::get::execute(&state.provider_deps, query)
+        .await?
+        .ok_or_else(|| ApiError::not_found(format!("Provider {id} not found")))?;
+    Ok(Json(ProviderConfigResponse::from(provider)))
+}
+
+/// PUT /admin/providers/:id
+pub async fn upsert_provider(
+    State(state): State<AppState>,
+    AdminUser(_user): AdminUser,
+    Path(id): Path<String>,
+    Json(req): Json<ProviderConfigRequest>,
+) -> Result<Json<serde_json::Value>, ApiError> {
+    let config_json = serde_json::to_string(&req.config)
+        .map_err(|e| ApiError::validation(format!("Invalid config JSON: {e}")))?;
+
+    let cmd = UpsertProviderCommand {
+        id,
+        provider_type: req.provider_type,
+        config_json,
+        enabled: req.enabled,
+    };
+    application::providers::upsert::execute(&state.provider_deps, cmd).await?;
+    Ok(Json(serde_json::json!({"status": "ok"})))
+}
+
+/// DELETE /admin/providers/:id
+pub async fn delete_provider(
+    State(state): State<AppState>,
+    AdminUser(_user): AdminUser,
+    Path(id): Path<String>,
+) -> Result<axum::http::StatusCode, ApiError> {
+    let cmd = DeleteProviderCommand { id };
+    application::providers::delete::execute(&state.provider_deps, cmd).await?;
+    Ok(axum::http::StatusCode::NO_CONTENT)
+}