feat: Implement module update functionality with a new API endpoint, client method, and @hello-pangea/dnd dependency.

services/cms-service/src/handlers.rs

@@ -880,3 +880,33 @@ pub async fn get_course_outline(
         modules: modules_with_lessons,
     }))
 }
+
+pub async fn update_module(
+    claims: common::auth::Claims,
+    State(pool): State<PgPool>,
+    Path(id): Path<Uuid>,
+    Json(payload): Json<serde_json::Value>,
+) -> Result<Json<Module>, StatusCode> {
+    let title = payload.get("title").and_then(|t| t.as_str());
+    let position = payload.get("position").and_then(|v| v.as_i64()).map(|v| v as i32);
+
+    let updated_module = sqlx::query_as::<_, Module>(
+        "UPDATE modules 
+         SET title = COALESCE($1, title), 
+             position = COALESCE($2, position)
+         WHERE id = $3 RETURNING *"
+    )
+    .bind(title)
+    .bind(position)
+    .bind(id)
+    .fetch_one(&pool)
+    .await
+    .map_err(|e| {
+        tracing::error!("Update module failed: {}", e);
+        StatusCode::INTERNAL_SERVER_ERROR
+    })?;
+
+    log_action(&pool, claims.sub, "UPDATE", "Module", id, json!(payload)).await;
+
+    Ok(Json(updated_module))
+}