feat(backend): implement job storage; tie everything up

backend/internal/storage/migrations.go

@@ -25,6 +25,20 @@ CREATE TABLE IF NOT EXISTS registration_tokens (
 );
 `
 
+const CreateJobsTable = `
+CREATE TABLE IF NOT EXISTS jobs (
+	id INTEGER PRIMARY KEY AUTOINCREMENT,
+	agent_id TEXT NOT NULL,
+	command TEXT NOT NULL,
+	stdin TEXT,
+	stdout TEXT DEFAULT '',
+	stderr TEXT DEFAULT '',
+	status INTEGER DEFAULT 0,
+	created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+	updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+);
+`
+
 const CreateLogsTable = `
 CREATE TABLE IF NOT EXISTS logs (
     timestamp DateTime64(3) DEFAULT now(),