refactor: replace get_stream_url with get_source_uri per ADR-0002

Providers now expose a source URI (for FFmpeg) instead of a
viewer-facing stream URL. Playout Service will own transcoding.

- Add SourceUri value object (NetworkUrl | FilePath)
- Remove StreamQuality, StreamingProtocol from domain
- Simplify ProviderCapabilities (drop streaming_protocol, transcode)
- Jellyfin: return static direct stream URL
- Local files: return absolute file path
- Rename use case get_stream_url -> get_source
- Stream endpoint returns JSON SourceUri instead of 307 redirect

crates/mcp/src/main.rs

@@ -1,7 +1,6 @@
 use std::sync::Arc;
 
-use domain::ports::{IMediaProvider, IProviderRegistry, ProviderCapabilities, StreamingProtocol};
-use domain::ports::StreamQuality;
+use domain::ports::{IMediaProvider, IProviderRegistry, ProviderCapabilities};
 use domain::{DomainError, DomainResult, MediaFilter, MediaItem, MediaItemId, ScheduleEngineService};
 use infra_wiring::DbPool;
 use tracing::info;
@@ -175,9 +174,7 @@ impl IMediaProvider for NoopMediaProvider {
             tags: false,
             decade: false,
             search: false,
-            streaming_protocol: StreamingProtocol::DirectFile,
             rescan: false,
-            transcode: false,
         }
     }
 
@@ -193,7 +190,7 @@ impl IMediaProvider for NoopMediaProvider {
         ))
     }
 
-    async fn get_stream_url(&self, _: &MediaItemId, _: &StreamQuality) -> DomainResult<String> {
+    async fn get_source_uri(&self, _: &MediaItemId) -> DomainResult<domain::SourceUri> {
         Err(DomainError::InfrastructureError(
             "No media provider configured.".into(),
         ))
@@ -254,19 +251,18 @@ impl IProviderRegistry for SimpleProviderRegistry {
         }
     }
 
-    async fn get_stream_url(
+    async fn get_source_uri(
         &self,
         item_id: &MediaItemId,
-        quality: &StreamQuality,
-    ) -> DomainResult<String> {
+    ) -> DomainResult<domain::SourceUri> {
         let id_str = item_id.value();
         if let Some(pid) = Self::extract_provider_id(id_str)
             && let Some(provider) = self.get(pid)
         {
-            return provider.get_stream_url(item_id, quality).await;
+            return provider.get_source_uri(item_id).await;
         }
         if let Some(provider) = self.primary() {
-            provider.get_stream_url(item_id, quality).await
+            provider.get_source_uri(item_id).await
         } else {
             Err(DomainError::InfrastructureError(
                 "No provider available".into(),