Release 0.5.6

What's Changed

• feat: support local a2a hub server and client by @yaozheng-fang in #438
• feat: integrate skills in veadk by @BhAem in #407
• fix: ignore empty string in skill by @BhAem in #439
• feat: add agent local examples by @yaozheng-fang in #441
• fix: add register skill tool and comment playwright tool by @BhAem in #442
• fix(model): responses-api expire time setting and docs by @zakahan in #443
• fix: add stdio in execute_skills tool by @BhAem in #445
• fix trusted mcp create_session by @zakahan in #446
• fix: fix knowledgebase credential get by @yaozheng-fang in #444
• fix(viking-kb): fix viking db got none responses by @yaozheng-fang in #447

Full Changelog: 0.5.5...0.5.6