refactor(runtime): add run DDD boundary skeleton

backend/packages/harness/deerflow/runtime/runs/domain/value_objects.py

@@ -0,0 +1,88 @@
+"""Domain value objects for run lifecycle semantics."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import StrEnum
+
+
+class RunStatus(StrEnum):
+    """Lifecycle status of a single run."""
+
+    pending = "pending"
+    running = "running"
+    success = "success"
+    error = "error"
+    timeout = "timeout"
+    interrupted = "interrupted"
+
+
+class DisconnectMode(StrEnum):
+    """Behaviour when the SSE consumer disconnects."""
+
+    cancel = "cancel"
+    continue_ = "continue"
+
+
+class RunScope(StrEnum):
+    """Conversation scope for a run."""
+
+    stateful = "stateful"
+    stateless = "stateless"
+    temporary_thread = "temporary_thread"
+
+
+class MultitaskStrategy(StrEnum):
+    """Concurrency strategy for a new run on a thread."""
+
+    reject = "reject"
+    interrupt = "interrupt"
+    rollback = "rollback"
+    enqueue = "enqueue"
+
+
+class CancelAction(StrEnum):
+    """Cancellation action requested by an API or supervisor."""
+
+    interrupt = "interrupt"
+    rollback = "rollback"
+
+
+TERMINAL_RUN_STATUSES: frozenset[RunStatus] = frozenset(
+    {
+        RunStatus.success,
+        RunStatus.error,
+        RunStatus.timeout,
+        RunStatus.interrupted,
+    }
+)
+
+
+def is_terminal_status(status: RunStatus) -> bool:
+    return status in TERMINAL_RUN_STATUSES
+
+
+@dataclass(frozen=True, order=True)
+class EventSeq:
+    """Thread-local event sequence number."""
+
+    value: int
+
+    def __post_init__(self) -> None:
+        if self.value < 0:
+            raise ValueError("EventSeq must be non-negative")
+
+    def next(self) -> EventSeq:
+        return EventSeq(self.value + 1)
+
+
+__all__ = [
+    "CancelAction",
+    "DisconnectMode",
+    "EventSeq",
+    "MultitaskStrategy",
+    "RunScope",
+    "RunStatus",
+    "TERMINAL_RUN_STATUSES",
+    "is_terminal_status",
+]