Move last opened file to workspaces table

backend/internal/db/migrations.go

@@ -22,8 +22,7 @@ var migrations = []Migration{
 			password_hash TEXT NOT NULL,
 			role TEXT NOT NULL CHECK(role IN ('admin', 'editor', 'viewer')),
 			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-			last_workspace_id INTEGER,
-			last_opened_file_path TEXT
+			last_workspace_id INTEGER
 		);
 
 		-- Create workspaces table with integrated settings
@@ -32,6 +31,7 @@ var migrations = []Migration{
 			user_id INTEGER NOT NULL,
 			name TEXT NOT NULL,
 			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+			last_opened_file_path TEXT,
 			-- Settings fields
 			theme TEXT NOT NULL DEFAULT 'light' CHECK(theme IN ('light', 'dark')),
 			auto_save BOOLEAN NOT NULL DEFAULT 0,