Add observed_channel_notes table and implement note diffing

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

@@ -0,0 +1,42 @@
+use crate::db::{ChannelId, UserId};
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
+#[sea_orm(table_name = "observed_channel_note_edits")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub user_id: UserId,
+    pub channel_id: ChannelId,
+    pub epoch: i32,
+    pub lamport_timestamp: i32,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(
+        belongs_to = "super::channel::Entity",
+        from = "Column::ChannelId",
+        to = "super::channel::Column::Id"
+    )]
+    Channel,
+    #[sea_orm(
+        belongs_to = "super::user::Entity",
+        from = "Column::UserId",
+        to = "super::user::Column::Id"
+    )]
+    User,
+}
+
+impl Related<super::channel::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Channel.def()
+    }
+}
+
+impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::User.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}