v3.9

What's Changed

• Add Sphinx documentation under docs/ by @AminMahpour in #111
• Add opt-in agent messaging and nonblocking user input by @AminMahpour in #113
• Docs: scope stateless persistence claim to agent state by @AminMahpour in #112
• Fix Chainlit turns cancelled on transient disconnect by @AminMahpour in #114
• fix(chainlit): show names for nested subagent tool steps by @AminMahpour in #115
• Speed up saved-chat resume with conversation-scoped MCP reuse by @AminMahpour in #116
• fix(chainlit): preserve work across saved-chat switches by @AminMahpour in #117
• chore(deps): bump deepagents to 0.7.21 by @AminMahpour in #118

Full Changelog: v3.8...v3.9