Let the agent spawn tasks from chat via TaskCreationSaga

[charlesvien]

Description

The agent should be able to spawn real tasks from a chat prompt. Example:

Spawn a task to do the charts work, the terraform work and the implementation using worktrees in the correct repos.

You would get real tasks in the sidebar that you can keep prompting, exactly as if you had made them yourself. The tasks must go through the existing TaskCreationSaga so they behave like normal tasks, not a side channel.

Raised by @haacked, who is happy to implement but wants to align on the approach first since it overlaps with work others are already circling.

Proposed solution

Give the agent a tool (e.g. spawn_tasks) that routes through TaskCreationSaga, so spawned tasks are indistinguishable from human-created ones.

Open questions

• Shared spawn entry point: Does RTS mode (feat(code-rts): introduce RTS mode — RTS-style agent orchestration UI #2299) want a spawn_tasks tool it can call, or is it already spawning another way? Same question for the orchestrator in Vojta's status-events PR.
• Blessed task-creation path: Confirm TaskCreationSaga is the standard way to create a task in code. Forking (feat(code): session forking #2322) rolls its own and skips the saga (external contributor branch). If there's a reason to steer clear of the saga, flag it before building on it.
• Agent to host call: Copy the existing permission round-trip, or ride the posthog-code-internal MCP server (feat(agent): self-modify via posthog-code-internal MCP + YAML-driven tool registry #2415)? Should match whatever is being standardized.

Related

• Spawn task from PR #1633 (Spawn task from PR) is adjacent but different: a human-initiated spawn from a PR view, not an agent-initiated spawn from chat.