Fix joining hosted projects (#9038)

Release Notes:

- N/A

crates/collab/src/db/tables/hosted_project.rs

@@ -15,4 +15,13 @@ pub struct Model {
 impl ActiveModelBehavior for ActiveModel {}
 
 #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
-pub enum Relation {}
+pub enum Relation {
+    #[sea_orm(has_one = "super::project::Entity")]
+    Project,
+}
+
+impl Related<super::project::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Project.def()
+    }
+}

crates/collab/src/db/tables/project.rs

@@ -50,6 +50,12 @@ pub enum Relation {
     Collaborators,
     #[sea_orm(has_many = "super::language_server::Entity")]
     LanguageServers,
+    #[sea_orm(
+        belongs_to = "super::hosted_project::Entity",
+        from = "Column::HostedProjectId",
+        to = "super::hosted_project::Column::Id"
+    )]
+    HostedProject,
 }
 
 impl Related<super::user::Entity> for Entity {
@@ -82,4 +88,10 @@ impl Related<super::language_server::Entity> for Entity {
     }
 }
 
+impl Related<super::hosted_project::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::HostedProject.def()
+    }
+}
+
 impl ActiveModelBehavior for ActiveModel {}