feat: real XMP sidecar adapter, replaces LogSidecarWriter stubs

- adapters-sidecar: XmpSidecarWriter using xmp_toolkit
- Writes StructuredData → XMP with EXIF/DC/XMP namespace routing
- Reads XMP back to StructuredData
- Wired into bootstrap + worker, deleted both LogSidecarWriter stubs

crates/bootstrap/src/lib.rs

@@ -1,4 +1,3 @@
 pub mod config;
 pub mod factory;
-pub mod log_sidecar_writer;
 pub mod services;

crates/bootstrap/src/log_sidecar_writer.rs

@@ -1,21 +0,0 @@
-use async_trait::async_trait;
-use domain::{errors::DomainError, ports::SidecarWriterPort, value_objects::StructuredData};
-
-pub struct LogSidecarWriter;
-
-#[async_trait]
-impl SidecarWriterPort for LogSidecarWriter {
-    fn format_name(&self) -> &str {
-        "log_noop"
-    }
-
-    async fn write_sidecar(&self, _data: &StructuredData, path: &str) -> Result<(), DomainError> {
-        tracing::info!(path, "sidecar write (no-op)");
-        Ok(())
-    }
-
-    async fn read_sidecar(&self, path: &str) -> Result<StructuredData, DomainError> {
-        tracing::info!(path, "sidecar read (no-op)");
-        Ok(StructuredData::new())
-    }
-}

crates/bootstrap/src/main.rs

@@ -3,7 +3,6 @@ use tracing::info;
 
 mod config;
 mod factory;
-mod log_sidecar_writer;
 mod services;
 
 #[tokio::main]

crates/bootstrap/src/services/sidecar.rs

@@ -9,13 +9,12 @@ use application::sidecar::{
 };
 use presentation::state::SidecarHandlers;
 
-use crate::log_sidecar_writer::LogSidecarWriter;
-
 pub fn build(pool: &PgPool) -> SidecarHandlers {
     let metadata_repo = Arc::new(PostgresAssetMetadataRepository::new(pool.clone()));
     let asset_repo = Arc::new(PostgresAssetRepository::new(pool.clone()));
     let sidecar_repo = Arc::new(PostgresSidecarRepository::new(pool.clone()));
-    let sidecar_writer: Arc<LogSidecarWriter> = Arc::new(LogSidecarWriter);
+    let sidecar_writer: Arc<adapters_sidecar::XmpSidecarWriter> =
+        Arc::new(adapters_sidecar::XmpSidecarWriter);
 
     let export = Arc::new(ExportSidecarHandler::new(
         metadata_repo.clone(),