feat: user slowmode events (#760)

* feat: user slowmode events

Signed-off-by: ispik <ispik@ispik.dev>

* fix: remove debug print statement for slowmodes

Signed-off-by: ispik <ispik@ispik.dev>

* refactor: Send user slowmodes as websocket connects instead of trying to send it in ready payload

Signed-off-by: ispik <ispik@ispik.dev>

* refactor: optimize user slowmode handling with bulk operations

Signed-off-by: ispik <ispik@ispik.dev>

* chore: specify release version

Release-As: 0.13.6

---------

Signed-off-by: ispik <ispik@ispik.dev>

crates/core/models/src/v0/channels.rs

@@ -314,6 +314,12 @@ auto_derived!(
         /// Only used when the user is the first one connected.
         pub recipients: Option<Vec<String>>,
     }
+
+    pub struct ChannelSlowmode {
+        pub channel_id: String,
+        pub duration: u64,
+        pub retry_after: u64,
+    }
 );
 
 impl Channel {