Feature 04 task 5: Async job runner and GET /api/v1/jobs/{id} (#29)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

migrations/queries/jobs.sql

@@ -0,0 +1,37 @@
+-- name: CreateJob :exec
+INSERT INTO jobs (id, kind, status, payload, created_at, updated_at)
+VALUES (?, ?, 'queued', ?, ?, ?);
+
+-- name: ClaimNextJob :one
+-- Marks the oldest queued job running and returns it. Returns sql.ErrNoRows
+-- when no job is queued.
+UPDATE jobs
+SET status = 'running', started_at = sqlc.arg(now), updated_at = sqlc.arg(now)
+WHERE id = (SELECT id FROM jobs WHERE status = 'queued' ORDER BY id LIMIT 1)
+RETURNING *;
+
+-- name: PublishJobResult :execrows
+-- Stores a partial result of a running job.
+UPDATE jobs
+SET result = ?, updated_at = ?
+WHERE id = ? AND status = 'running';
+
+-- name: SucceedJob :execrows
+UPDATE jobs
+SET status = 'succeeded', result = sqlc.arg(result), finished_at = sqlc.arg(now), updated_at = sqlc.arg(now)
+WHERE id = sqlc.arg(id) AND status = 'running';
+
+-- name: FailJob :execrows
+UPDATE jobs
+SET status = 'failed', error = sqlc.arg(error), finished_at = sqlc.arg(now), updated_at = sqlc.arg(now)
+WHERE id = sqlc.arg(id) AND status = 'running';
+
+-- name: FailRunningJobs :execrows
+-- Fails every job left running, at boot before any worker starts.
+UPDATE jobs
+SET status = 'failed', error = sqlc.arg(error), finished_at = sqlc.arg(now), updated_at = sqlc.arg(now)
+WHERE status = 'running';
+
+-- name: GetJob :one
+SELECT * FROM jobs
+WHERE id = ?;