Best possible solution:

Land this after normal maintainer approval and required checks if the product decision to repurpose top-level /steer for current-session runs is accepted.

Do we have a high-confidence way to reproduce the issue?

Not applicable. This is a new command feature rather than a reported bug; the review path is static diff inspection plus the focused command tests listed in the PR body.

Is this the best way to solve the issue?

Yes. The proposed implementation is narrow: it reuses the existing active-run registry and queueing APIs, leaves child-run steering under subagent dispatch, and updates the registry/docs/tests for the changed command contract.

What I checked:

• Top-level handler registration: The PR imports handleSteerCommand and places it before handleSubagentsCommand, so /steer is claimed by the current-session command path before subagent routing. (src/auto-reply/reply/commands-handlers.runtime.ts:57, a76acf95acfd)
• Current-session steering implementation: The added handler parses /steer and /tell, checks command authorization, resolves the current target session key, refuses idle sessions, and queues guidance with steeringMode: "all" and debounceMs: 0. (src/auto-reply/reply/commands-steer.ts:67, a76acf95acfd)
• Existing active-run API supports the approach: Current main already exposes active embedded run resolution and queueing; queueEmbeddedPiMessage returns false when there is no accepting active run, matching the PR's idle/rejection handling. (src/agents/pi-embedded-runner/runs.ts:66, 5355ef0f080b)
• Subagent routing split is explicit: Current main routes /steer and /tell through subagent dispatch; the PR removes those top-level aliases from subagent dispatch and leaves steer as a /subagents action. (src/auto-reply/reply/commands-subagents/shared.ts:169, 5355ef0f080b)
• Registry and docs are updated: The command registry changes steer from target-plus-message to message-only while preserving /tell as a text alias; the PR also updates slash-command docs, subagent docs, changelog, and focused tests. (src/auto-reply/commands-registry.shared.ts:512, a76acf95acfd)
• Validation context: The PR body reports focused command tests, targeted formatting, git diff --check, and Testbox pnpm check:changed passing for the head SHA. (a76acf95acfd)

Likely related people:

• steipete: Recent main history shows substantial command-registry, subagent helper, and active steering work in the same surfaces affected by this PR. (role: recent maintainer and adjacent feature owner; confidence: high; commits: 2805bbd3d7a9, 30a2b3049ae0, bf67976ea58e; files: src/auto-reply/commands-registry.shared.ts, src/auto-reply/reply/commands-subagents/shared.ts, src/agents/pi-embedded-runner/runs.ts)
• vincentkoc: Recent commits touched embedded runner import/lifecycle behavior that the new current-session steering command depends on. (role: adjacent embedded-run maintainer; confidence: medium; commits: 4a30ae182b6a, ec1f72b6c58f; files: src/agents/pi-embedded-runner/runs.ts)
• drobison00: Recent merged work changed subagent focus scope in the same subagent command helper area. (role: adjacent subagent routing maintainer; confidence: medium; commits: c1a42dce86cb; files: src/auto-reply/reply/commands-subagents/shared.ts)

Codex review notes: model gpt-5.5, reasoning high; reviewed against 5355ef0f080b.