Remove logic for multiple channel parents

Co-authored-by: Conrad <conrad@zed.dev>
Co-authored-by: Kyle <kyle@zed.dev>
Co-authored-by: Joseph <joseph@zed.dev>

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

@@ -8,6 +8,28 @@ pub struct Model {
     pub id: ChannelId,
     pub name: String,
     pub visibility: ChannelVisibility,
+    pub parent_path: String,
+}
+
+impl Model {
+    pub fn parent_id(&self) -> Option<ChannelId> {
+        self.ancestors().last()
+    }
+
+    pub fn ancestors(&self) -> impl Iterator<Item = ChannelId> + '_ {
+        self.parent_path
+            .trim_end_matches('/')
+            .split('/')
+            .filter_map(|id| Some(ChannelId::from_proto(id.parse().ok()?)))
+    }
+
+    pub fn ancestors_including_self(&self) -> impl Iterator<Item = ChannelId> + '_ {
+        self.ancestors().chain(Some(self.id))
+    }
+
+    pub fn path(&self) -> String {
+        format!("{}{}/", self.parent_path, self.id)
+    }
 }
 
 impl ActiveModelBehavior for ActiveModel {}

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

@@ -1,15 +0,0 @@
-use crate::db::ChannelId;
-use sea_orm::entity::prelude::*;
-
-#[derive(Clone, Debug, Default, PartialEq, Eq, DeriveEntityModel)]
-#[sea_orm(table_name = "channel_paths")]
-pub struct Model {
-    #[sea_orm(primary_key)]
-    pub id_path: String,
-    pub channel_id: ChannelId,
-}
-
-impl ActiveModelBehavior for ActiveModel {}
-
-#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
-pub enum Relation {}