refactor(runtime): restructure runs module with new execution architecture

Major refactoring of deerflow/runtime/:
- runs/callbacks/ - new callback system (builder, events, title, tokens)
- runs/internal/ - execution internals (executor, supervisor, stream_logic, registry)
- runs/internal/execution/ - execution artifacts and events handling
- runs/facade.py - high-level run facade
- runs/observer.py - run observation protocol
- runs/types.py - type definitions
- runs/store/ - simplified store interfaces (create, delete, query, event)

Refactor stream_bridge/:
- Replace old providers with contract.py and exceptions.py
- Remove async_provider.py, base.py, memory.py

Add documentation:
- README.md and README_zh.md for runtime module

Remove deprecated:
- manager.py moved to internal/
- worker.py, schemas.py
- user_context.py

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/packages/harness/deerflow/runtime/runs/__init__.py

@@ -1,16 +1,48 @@
-"""Run lifecycle management for LangGraph Platform API compatibility."""
+"""Public runs API."""
 
-from .manager import ConflictError, RunManager, RunRecord, UnsupportedStrategyError
-from .schemas import DisconnectMode, RunStatus
-from .worker import RunContext, run_agent
+from .facade import RunsFacade
+from .internal.manager import RunManager
+from .observer import (
+    CallbackObserver,
+    CompositeObserver,
+    LifecycleEventType,
+    NullObserver,
+    ObserverBinding,
+    ObserverLike,
+    RunEventCallback,
+    RunLifecycleEvent,
+    RunObserver,
+    RunResult,
+    ensure_observer,
+)
+from .store import RunCreateStore, RunDeleteStore, RunEventStore, RunQueryStore
+from .types import CancelAction, RunRecord, RunScope, RunSpec, RunStatus, WaitResult
 
 __all__ = [
-    "ConflictError",
-    "DisconnectMode",
-    "RunContext",
+    # facade
+    "RunsFacade",
     "RunManager",
+    "RunCreateStore",
+    "RunDeleteStore",
+    "RunEventStore",
+    "RunQueryStore",
+    # hooks
+    "CallbackObserver",
+    "CompositeObserver",
+    "LifecycleEventType",
+    "NullObserver",
+    "ObserverBinding",
+    "ObserverLike",
+    "RunEventCallback",
+    "RunLifecycleEvent",
+    "RunObserver",
+    "RunResult",
+    "ensure_observer",
+    # types
+    "CancelAction",
     "RunRecord",
+    "RunScope",
+    "RunSpec",
+    "WaitResult",
     "RunStatus",
-    "UnsupportedStrategyError",
-    "run_agent",
 ]