refactor(tests): reformat code and update dependency management

- Reorganized import statements in adapter tests for better readability
- Replaced or_insert_with(Vec::new) with or_default() in test closures
- Updated Cargo.lock with new dependency versions and checksums
- Added TLS features to tonic dependency configuration
- Included sqlx, chrono, and uuid dependencies with specific features
- Added jsonwebtoken and arc-swap as project dependencies
- Reformatted assertion statements to comply with line length limits
- Adjusted base64 import order in engine codec module
- Updated protobuf include statement formatting

models/message_draft.rs

@@ -0,0 +1,77 @@
+//! Message drafts — maps to `message_draft` table.
+//!
+//! Stores unsent messages so they survive browser refreshes and sync across
+//! the user's connected devices. One draft per (channel, user, optional thread).
+//! Drafts are upserted on every keystroke debounce and deleted on send.
+
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+/// A user's unsent message draft in a channel.
+#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
+pub struct MessageDraft {
+    pub id: Uuid,
+    pub channel_id: Uuid,
+    pub user_id: Uuid,
+    /// Thread the draft belongs to (NULL = top-level).
+    pub thread_id: Option<Uuid>,
+    /// Message this draft is replying to (NULL = new message).
+    pub reply_to_message_id: Option<Uuid>,
+    /// Plain text or markdown body.
+    pub body: String,
+    /// Extensible metadata (attachments to be uploaded, etc.).
+    pub metadata: Option<serde_json::Value>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// Input for upserting a draft (sent from client on debounced keystroke).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DraftUpsertInput {
+    pub channel_id: Uuid,
+    pub thread_id: Option<Uuid>,
+    pub reply_to_message_id: Option<Uuid>,
+    pub body: String,
+    pub metadata: Option<serde_json::Value>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_draft_upsert_input_serialize() {
+        let input = DraftUpsertInput {
+            channel_id: Uuid::now_v7(),
+            thread_id: None,
+            reply_to_message_id: None,
+            body: "hello, this is a draft".to_string(),
+            metadata: None,
+        };
+
+        let json = serde_json::to_value(&input).unwrap();
+        assert_eq!(json["body"], "hello, this is a draft");
+        assert!(json["thread_id"].is_null());
+    }
+
+    #[test]
+    fn test_draft_serialize() {
+        let draft = MessageDraft {
+            id: Uuid::now_v7(),
+            channel_id: Uuid::now_v7(),
+            user_id: Uuid::now_v7(),
+            thread_id: Some(Uuid::now_v7()),
+            reply_to_message_id: None,
+            body: "draft body".to_string(),
+            metadata: Some(serde_json::json!({"pending_attachments": []})),
+            created_at: Utc::now(),
+            updated_at: Utc::now(),
+        };
+
+        let json = serde_json::to_value(&draft).unwrap();
+        assert_eq!(json["body"], "draft body");
+        assert!(json["thread_id"].is_string());
+        assert!(json["metadata"]["pending_attachments"].is_array());
+    }
+}