refactor(db): add sqlx-migrate-validate and optimize backup logic

This commit introduces the `sqlx-migrate-validate` dependency to validate migrations before performing a database backup. The backup logic in `DbConn::new` has been refactored to only proceed with the backup if migrations are needed, improving efficiency and reducing unnecessary operations.

ee/tabby-db/Cargo.toml

@@ -26,6 +26,7 @@ sqlx = { workspace = true, features = [
     "macros",
     "json",
 ] }
+sqlx-migrate-validate = { path = "../../crates/sqlx-migrate-validate" }
 
 [dev-dependencies]
 assert_matches.workspace = true

ee/tabby-db/src/lib.rs

@@ -151,20 +151,28 @@ impl DbConn {
 
     pub async fn new(db_file: &Path) -> Result<Self> {
         tokio::fs::create_dir_all(db_file.parent().unwrap()).await?;
-        Self::backup_db(db_file).await?;
 
         let options = SqliteConnectOptions::new()
             .filename(db_file)
             .create_if_missing(true);
         let pool = SqlitePool::connect_with(options).await?;
+        Self::backup_db(db_file, &pool).await?;
         Self::init_db(pool).await
     }
 
     /// Backup existing database file before opening it.
     /// backup format:
     /// for prod - db.backup-${date}.sqlite
     /// for non-prod - dev-db.backup-${date}.sqlite
-    async fn backup_db(db_file: &Path) -> Result<()> {
+    async fn backup_db(db_file: &Path, pool: &SqlitePool) -> Result<()> {
+        use sqlx_migrate_validate::{Validate, Validator};
+
+        let mut conn = pool.acquire().await?;
+        if sqlx::migrate!("./migrations").validate(&mut *conn).await.is_ok() {
+            // No migration is needed, skip the backup.
+            return Ok(())
+        }
+
         if !tokio::fs::try_exists(db_file).await? {
             return Ok(());
         }