[lawrencecchen]

Summary

The arch ratchet's layer_unplaced is 3 at feat-cmux-next, against a record of 0. Three Package.swift targets have no entry in plans/cmux-next/architecture-layers.json, so the layer gate and the edge rows cannot judge their edges. This PR places each one at the highest layer it holds (the map's rule). No exception.

Target	Added by	Layer	Why
CmuxNextAppCore	66946e0	ui, mixes service and domain	Seam protocols for app features; its public interface names AgentPane and Sidebar (ui) types; only CmuxNextApp imports it
CmuxNextSessionTransfer	ec1311e (#20945)	ui, mixes core	Sendable transfer values and the Move Sessions picker as data (no state); its public interface returns Design's CmuxDialogSpec
CmuxNextUiLayerPreview	fe5fcb8 (#24978)	ui	Debug-only SwiftUI preview leaf on Design and Icons

Every edge points to the same or a lower layer, so the hard, soft and upward edge counts stay 34, 12 and 3.

A follow-up could make CmuxNextAppCore domain. It holds no views, but its public interface uses ui types: AgentPaneSeed and SidebarRowSection (ui targets) and NSWindow? (WorkspaceSelectionCloseFlow.swift, public import AppKit). Those must move or go before a relabel, or it adds 2 hard edges and fails the relabel proof.

The same placement (without SessionTransfer, which perf does not have) is on perf/chrome-parity in cp/fix-tip-cmux-tui-gen-checks.

Changelog

none

Testing

• Unplaced targets (arch_counts layers() at the head's manifests): base ['CmuxNextAppCore', 'CmuxNextSessionTransfer', 'CmuxNextUiLayerPreview'], head [].
• Edge rows: hard 34 -> 34, soft 12 -> 12, upward 3 -> 3.
• python3 scripts/cmux-next/tests/test_layer_gate.py: OK.
• python3 scripts/cmux-next/prepush-gate.py: no new violations, no architecture count rises.

Observed / Not run

• Observed: the commands above on Linux (cmux-orchestrator-1, Python 3.12), at the base cec0a36 and the head.
• Not run: no build; this changes only the layer map JSON.

[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review 2cb910e: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr27805 -f ref=fix/arch-layers-appcore-uilayerpreview -f platform=macos -f backend_mode=local

red: cmux-next checks (god files, concurrency, crash safety, l10n); NEW: green on the base cec0a36; do not merge until green; see lane-rules

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4115488208801 (dd66817742)
• cmux NEXT nightly 1.0.0-nightly.4115755828101 (7c0adaf184)

[lawrencecchen]

Independent review subagent (correctness first): SHIP. Each target is placed at the highest layer it holds; none can go lower without new hard edges. arch_counts layers(): unplaced 3 -> 0; hard 34, soft 12, upward 3, with identical edge sets. test_layer_gate.py OK (55); layer_gate.py ok. Delta 23b6d8f..2cb910e (SessionTransfer mixes core, body fixes) also checked.

Review (Claude Opus 5.5): SHIP at 2cb910e

[blacksmith-sh]

Found 7 test failures on Blacksmith runners:

Failures

Test	View Logs
/tmp/tmp3ej33js1/summary-missing.json (live):/summary-missing.json (live):	View Logs
/tmp/tmp9b7441wa/summary-fail.json (live):/summary-fail.json (live):	View Logs
[new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows/ [new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows	View Logs
[new_workspaces] the window draws no frames/[new_workspaces] the window draws no frames	View Logs
[tabs] debug.tab_switch timed 0 of 40 switches/ [tabs] debug.tab_switch timed 0 of 40 switches	View Logs
[tabs] the window draws no frames/[tabs] the window draws no frames	View Logs
convention violations found (ERROR lines above)./ convention violations found (ERROR lines above).	View Logs

^{Need help on this PR? Tag @codesmith-bot with what you need.}

[teamleaderleo]

Review (codex gpt-6-astra high fast, drain lane): SHIP at 2cb910e

No blocking findings.