docs(mcp): document existing recurring-task tools#23206

docs: clarify scheduled task thread binding defaults

Merge remote-tracking branch 'origin/main' into fix/issue-15670

docs(mcp): scheduled-task note warns that unsigned webhook URLs trigger runs

Merge main into fix/issue-15670

docs(mcp): scheduled-task note states webhook gates, server time zone, and unbound runs

docs(mcp): orchestrator MCP doc points at the toolkit and covers scheduled tasks