fix: harden queue lifecycle and publish gate

- Preserve phase results on partial retry and keep interrupted phase
  context after restart.
- Avoid webhook bookkeeping crashes when retention deletes stale jobs.
- Add deeper unit, integration, and e2e coverage around queue seams.
- Require verify job to pass before publish runs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docs/jobqueue.c4

@@ -0,0 +1,140 @@
+specification {
+  element actor {
+    style {
+      shape person
+    }
+  }
+
+  element system {
+    style {
+      shape rectangle
+    }
+  }
+
+  element container {
+    style {
+      shape rectangle
+    }
+  }
+
+  element component {
+    style {
+      shape component
+    }
+  }
+
+  element database {
+    style {
+      shape storage
+    }
+  }
+
+  relationship async {
+    color amber
+    line dotted
+  }
+}
+
+model {
+  consumer = actor "Consumer application"
+  webhookReceiver = system "Webhook receiver"
+
+  jobqueue = system "jobqueue" {
+    api = container "Public API" {
+      technology "ESM / TypeScript"
+      description "JobQueue constructor plus enqueue, retry, cancel, query, stream, shutdown APIs"
+    }
+
+    runtime = container "Runtime orchestrator" {
+      technology "Node.js"
+      description "Coordinates persistence, execution, retries, events, SSE, webhooks, and shutdown"
+
+      queue = component "JobQueue"
+      storage = component "SqliteStorage"
+      pool = component "WorkerPool"
+      runner = component "PhaseRunner"
+      retry = component "RetryStrategy"
+      events = component "TypedEventBus"
+      sse = component "SseSerializer"
+      retention = component "RetentionScheduler"
+      webhooks = component "WebhookDispatcher"
+
+      queue -> storage "persists job state"
+      queue -> pool "dispatches runnable jobs"
+      queue -> runner "executes phase pipeline"
+      queue -> retry "classifies failures"
+      queue -> events "emits typed queue events"
+      queue -> sse "serializes SSE payloads"
+      queue -> retention "runs stale/delete cycle"
+      queue -[async]-> webhooks "dispatches outbound callbacks"
+    }
+
+    sqlite = database "SQLite jobs database" {
+      technology "better-sqlite3 + WAL"
+    }
+
+    handlers = container "Registered phase handlers" {
+      technology "Consumer-provided async functions"
+    }
+
+    streams = container "SSE subscribers" {
+      technology "ReadableStream consumers"
+    }
+
+    api -> runtime.queue "constructs and invokes"
+    runtime.storage -> sqlite "reads/writes rows"
+    runtime.runner -> handlers "invokes phase handlers"
+    runtime.events -> streams "pushes queue events"
+  }
+
+  consumer -> jobqueue.api "enqueue / retry / cancel / inspect / subscribe"
+  jobqueue.runtime.webhooks -[async]-> webhookReceiver "POST job events"
+}
+
+views {
+  view index {
+    title "jobqueue landscape"
+    include *
+    autoLayout LeftRight
+  }
+
+  view library of jobqueue {
+    title "jobqueue containers"
+    include *
+    autoLayout LeftRight
+  }
+
+  view runtime of jobqueue.runtime {
+    title "jobqueue runtime components"
+    include *
+    autoLayout LeftRight
+  }
+
+  dynamic view enqueue-to-complete {
+    title "Enqueue to successful completion"
+    consumer -> jobqueue.api "enqueue()"
+    jobqueue.api -> jobqueue.runtime.queue "create job"
+    jobqueue.runtime.queue -> jobqueue.runtime.storage "persist pending row"
+    jobqueue.runtime.queue -> jobqueue.runtime.pool "schedule worker"
+    jobqueue.runtime.pool -> jobqueue.runtime.runner "run phases"
+    jobqueue.runtime.runner -> jobqueue.handlers "invoke handler(s)"
+    jobqueue.runtime.runner -> jobqueue.runtime.storage "persist progress + phase results"
+    jobqueue.runtime.queue -> jobqueue.runtime.events "emit queue events"
+    jobqueue.runtime.events -> jobqueue.streams "push SSE"
+    jobqueue.runtime.queue -> jobqueue.runtime.webhooks "send completion webhook"
+    jobqueue.runtime.webhooks -> webhookReceiver "POST payload"
+    jobqueue.runtime.queue -> jobqueue.runtime.storage "mark webhook_sent"
+  }
+
+  dynamic view retry-flow {
+    title "Failure and retry flow"
+    jobqueue.runtime.runner -> jobqueue.handlers "invoke handler"
+    jobqueue.handlers -> jobqueue.runtime.queue "throw recoverable error"
+    jobqueue.runtime.queue -> jobqueue.runtime.retry "classify error"
+    jobqueue.runtime.retry -> jobqueue.runtime.queue "retry with delay"
+    jobqueue.runtime.queue -> jobqueue.runtime.storage "persist pending retry"
+    jobqueue.runtime.queue -> jobqueue.runtime.events "emit job:retrying"
+    jobqueue.runtime.events -> jobqueue.streams "push SSE"
+    jobqueue.runtime.queue -[async]-> jobqueue.runtime.webhooks "dispatch retry webhook"
+  }
+}