MediaRole auto-detection + manual role API + sync wiring (#7)

role_detector: classify items as Interstitial by collection name/tag patterns.
Wire chapter extraction + role detection into sync adapter (worker + presentation).
SQLite: persist/read role column, migration.
PUT /library/items/{id}/role endpoint for manual override.

crates/presentation/src/handlers/library.rs

@@ -4,9 +4,10 @@ use axum::extract::{Path, Query, State};
 use api_types::{
     CollectionResponse, GenresParams, LibraryItemResponse, LibrarySearchParams, PaginatedResponse,
     ProviderParam, SeasonResponse, SeasonsParams, ShowResponse, ShowsParams, SyncStatusEntry,
+    UpdateRoleRequest,
 };
 use application::library::{SearchItemsQuery, TriggerSyncCommand};
-use domain::DomainError;
+use domain::{DomainError, MediaRole};
 
 use crate::errors::AppError;
 use crate::extractors::{AdminUser, CurrentUser};
@@ -131,3 +132,32 @@ pub async fn trigger_sync(
     application::library::sync::execute(&state.library_command_deps, cmd).await?;
     Ok(axum::http::StatusCode::ACCEPTED)
 }
+
+pub async fn update_role(
+    State(state): State<AppState>,
+    AdminUser(_user): AdminUser,
+    Path(id): Path<String>,
+    Json(body): Json<UpdateRoleRequest>,
+) -> Result<Json<LibraryItemResponse>, AppError> {
+    let role: MediaRole = serde_json::from_value(serde_json::Value::String(body.role.clone()))
+        .map_err(|_| {
+            AppError(DomainError::ValidationError(format!(
+                "Invalid role '{}'. Must be 'program' or 'interstitial'",
+                body.role
+            )))
+        })?;
+
+    state
+        .library_command_deps
+        .library_command
+        .update_role(&id, role)
+        .await?;
+
+    let item = state
+        .library_query
+        .get_by_id(&id)
+        .await?
+        .ok_or_else(|| AppError(DomainError::NotFound(format!("Library item {id} not found"))))?;
+
+    Ok(Json(LibraryItemResponse::from(item)))
+}