feat: establish Orbit models, migrations and development baseline

weave/model/state.go

@@ -0,0 +1,74 @@
+package model
+
+// InstanceState 描述流程执行状态，独立的 Paused 标记控制是否允许新工作。
+type InstanceState string
+
+const (
+	InstanceRunning     InstanceState = "RUNNING"
+	InstanceWaiting     InstanceState = "WAITING"
+	InstanceCancelling  InstanceState = "CANCELLING"
+	InstanceNeedsReview InstanceState = "NEEDS_REVIEW"
+	InstanceSucceeded   InstanceState = "SUCCEEDED"
+	InstanceFailed      InstanceState = "FAILED"
+	InstanceCancelled   InstanceState = "CANCELLED"
+)
+
+func (s InstanceState) Terminal() bool {
+	return s == InstanceSucceeded || s == InstanceFailed || s == InstanceCancelled
+}
+func (i Instance) AllowsNewWork() bool {
+	return !i.Paused && i.CancelRequestedAt == nil && (i.State == InstanceRunning || i.State == InstanceWaiting)
+}
+
+type NodeKind string
+
+const (
+	NodeTask     NodeKind = "TASK"     // 通过 Pulse 执行业务处理器。
+	NodeBranch   NodeKind = "BRANCH"   // 按已保存结果选择条件路径。
+	NodeParallel NodeKind = "PARALLEL" // 展开有界并行分支。
+	NodeJoin     NodeKind = "JOIN"     // 按规则汇合并行结果。
+	NodeSignal   NodeKind = "SIGNAL"   // 等待业务信号。
+	NodeTimer    NodeKind = "TIMER"    // 等待指定时间。
+	NodePoll     NodeKind = "POLL"     // 有界重复查询节点。
+)
+
+type StepState string
+
+const (
+	StepBlocked     StepState = "BLOCKED"
+	StepReady       StepState = "READY"
+	StepActive      StepState = "ACTIVE"
+	StepWaiting     StepState = "WAITING"
+	StepNeedsReview StepState = "NEEDS_REVIEW"
+	StepSucceeded   StepState = "SUCCEEDED"
+	StepFailed      StepState = "FAILED"
+	StepCancelled   StepState = "CANCELLED"
+	StepSkipped     StepState = "SKIPPED"
+)
+
+type WaitState string
+
+const (
+	WaitWaiting   WaitState = "WAITING"
+	WaitSatisfied WaitState = "SATISFIED"
+	WaitExpired   WaitState = "EXPIRED"
+	WaitCancelled WaitState = "CANCELLED"
+)
+
+type SignalState string
+
+const (
+	SignalPending  SignalState = "PENDING"
+	SignalConsumed SignalState = "CONSUMED"
+	SignalExpired  SignalState = "EXPIRED"
+	SignalRejected SignalState = "REJECTED"
+)
+
+type InboxState string
+
+const (
+	InboxPending     InboxState = "PENDING"
+	InboxLeased      InboxState = "LEASED"
+	InboxProcessed   InboxState = "PROCESSED"
+	InboxQuarantined InboxState = "QUARANTINED"
+)