Tracking: subagent lifecycle PRs (#579 → #576 → #580 → #581) — merge order, conflict map, rebase plan

Summary

Four currently-open PRs from me form one coordinated subagent lifecycle roadmap. They are semantically orthogonal features, but they all extend the same agent-core plumbing (PilotDeckSubagentForkApi, SubAgentSession, AgentLoop), so they overlap textually and need an explicit merge sequence. This issue tracks the proposed order, the measured conflict map, and the rebase/validation plan, so maintainers can sequence reviews instead of discovering conflicts one merge at a time.

Measured conflict map

Actual test merges (pairwise, each PR merged on top of the other; base 97633a0):

Core files involved: AgentLoop.ts, SubAgentSession.ts, agent.ts, AgentRuntimeDependencies.ts, tool/protocol/types.ts; the only UI overlap is modelPool/types/index.ts between #576 and #579.

Against current main (e5bfb3fe): #576, #579, #580 merge cleanly. #581 has a single-file conflict in AgentLoop.ts caused by recent upstream movement in that region — I will rebase that branch (see checklist).

All conflicts are in additive extensions of the same types/fork-API entry points; each resolution is small. #580 + #581 are additionally validated merged together on an integration branch in my fork (work/subagent-lifecycle-integration) with both test suites re-run.

Proposed merge order

#579 → #576 → #580 → #581

Rationale:

1. #579 is the smallest, UI-only, and clean against everything except one shared UI file with #576 — a fast first merge.
2. #576 is the foundation the later two conceptually build on (role catalog, model binding, fork-API plumbing) and is clean against current main.
3. #580 next; its rebase after #576 is the largest (4 files) but the changes are orthogonal in intent.
4. #581 last; it needs a small rebase against current main regardless, and the #580+#581 combination is already validated together.

Any other order works too — I will rebase the remaining branches onto main after each merge and re-run the targeted test suites (agent/subagent specs + settings UI specs) before updating the PRs.

Checklist

• #579 merged
• #576 merged (rebase after #579: 1 UI file)
• #580 merged (rebase after #576: 4 core files)
• #581 merged (rebase after #576 + #580, plus current-main rebase in AgentLoop.ts)
• Re-run combined lifecycle validation (continuation + background) on the result

Happy to re-sequence if maintainers prefer a different order or want some of these consolidated.

Start with the conflict map and checklist, then inspect AgentLoop.ts, SubAgentSession.ts, agent.ts, AgentRuntimeDependencies.ts, and tool/protocol/types.ts. Follow the proposed PR order and review the targeted agent/subagent and settings UI test suites. Done means the four PRs are sequenced, rebased as needed, merged, and combined lifecycle validation has passed.