chore(release/v2-candidate): release 2.0.0-beta.1

[Jacksunwei]

2.0.0-beta.1 (2026-04-21)

Highlights

• Transition to Beta: Updated documentation to reflect the project's move to Beta phase (84e792fd).
• Security Fix: Resolved a potential RCE vulnerability related to nested YAML configurations (2b54c4ac).
• Documentation & Style: Modularized the ADK style guide and added new topics (9bb21795).
• Workflow Orchestration Core:
  • Added the full Workflow(BaseNode) graph orchestration implementation (c25d86f1).
  • Introduced NodeRunner for per-node execution isolation (0b3e7043).
  • Added DefaultNodeScheduler for standalone node resume via ctx.run_node() (a68e70d5).
• Agent Execution Models:
  • Added explicit ReAct loop nodes to replace legacy single agent flows (94453619).
  • Supported BaseNode as the root in both the Runner and the CLI (91b56b9a, 1c2a81bb).
• State & Resumption:
  • Added Human-in-the-loop (HITL) resume via event reconstruction (ca327329).
  • Added lazy scan deduplication and resume for dynamic nodes (d600b195).
  • Supported flushing state/artifact deltas onto yielded events (00153088).
• Performance:
  • Optimized execution by bypassing the Mesh for leaf single-turn LlmAgent instances (d864917f).