feat: async task pipeline for media and llm workflows

drizzle/0005_lively_taskmaster.sql

@@ -0,0 +1,22 @@
+CREATE TABLE `background_tasks` (
+	`id` varchar(36) NOT NULL,
+	`userId` int NOT NULL,
+	`type` enum('media_finalize','training_plan_generate','training_plan_adjust','analysis_corrections','pose_correction_multimodal') NOT NULL,
+	`status` enum('queued','running','succeeded','failed') NOT NULL DEFAULT 'queued',
+	`title` varchar(256) NOT NULL,
+	`message` text,
+	`progress` int NOT NULL DEFAULT 0,
+	`payload` json NOT NULL,
+	`result` json,
+	`error` text,
+	`attempts` int NOT NULL DEFAULT 0,
+	`maxAttempts` int NOT NULL DEFAULT 3,
+	`workerId` varchar(96),
+	`runAfter` timestamp NOT NULL DEFAULT (now()),
+	`lockedAt` timestamp,
+	`startedAt` timestamp,
+	`completedAt` timestamp,
+	`createdAt` timestamp NOT NULL DEFAULT (now()),
+	`updatedAt` timestamp NOT NULL DEFAULT (now()) ON UPDATE CURRENT_TIMESTAMP,
+	CONSTRAINT `background_tasks_id` PRIMARY KEY(`id`)
+);