feat(harness): Phase 1 — management foundation, fork & duplicate, drift detection

[eyelock]

First slice of the harness-as-first-class-citizen rework. Establishes the
architecture, surfaces, and YNH coordination model that Phase 2 (YND tools)
and Phase 3 (LLM authoring) will build on. Headed for 0.10 beta.

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What's in

Foundation

• CommandRunner — streamed-output shell-out with cancellation; single seam for all ynh/ynd callers (replaces ad-hoc Process/Pipe).
• YNH 0.3+ envelope decoding — HarnessListResponse/HarnessInfoResponse parse capabilities, ynh_version, and the new --check-updates fields (version_available, ref_available, sha_available).
• YnhVersionProbe — capability-based gate (≥ 0.3.0). Phase 1 features hidden silently on older binaries.
• Tolerant Harness decoder — accepts null for includes/delegates_to (which YNH emits for broken-install error rows). One bad row no longer collapses the sidebar.

Detail pane

• HarnessDetailViewModel extracted from the view — pure types own source classification, editability, and update signals, each with their own test coverage. Old feature-flagged badge retired.
• Source badges: registry name / short Git URL / Local / Forked from <X>. Read-only pill on registry installs.
• Vendor override picker — per-harness vendor (claude/codex/cursor) persists across launches, surfaces in the detail header.

Update detection — three-state drift signal

• Versioned (version_installed != version_available) — orange dot, info banner, single-click Update.
• Unversioned drift (content drift without a version bump) — amber warning triangle, warning banner, confirmation step listing each drifted include installed → available SHA. Surfaces the supply-chain signal explicitly so users review before pulling.
• None — clean.

Sidebar dots/triangles, header global-probe spinner, and the dependency-view per-include warning triangle all read from the same HarnessUpdateSignal.

Fork & Duplicate (pointer-model YNH)

Phase 1 lands alongside YNH's pointer-model rewrite (ynh fork --to <path> self-registers via ~/.ynh/installed/<name>.json).

• Fork to local — single ynh fork call. One editable working tree. No copy under ~/.ynh/harnesses/. installed_from.forked_from preserved for the ghost-origin display.
• Duplicate — single ynh fork --to <path> --name <newname> call. Local-only renamed copies. Hidden for registry harnesses (Fork covers that intent).
• Update menu hidden for forks (YNH refuses).

Action menu parity

Sidebar context menu and detail action menu share a canonical five-group layout. Sidebar drops Help and Export-as-Marketplace (advanced/help-only); detail keeps everything.

Group	Sidebar	Detail
Run	Launch / Copy Run Command	Copy Run Command
Location	Reveal in Finder, Reveal in Terminal, Open in…, Open in browser*, Copy as Pathname	same
Actions	Update*, Fork to local*, Duplicate*	+ Export as Marketplace…
Help	—	YNH Documentation
Destructive	Uninstall, Delete Harness*	same

* denotes context-gated visibility (URL-only, source-kind, fork-state, etc.)

Editable-path resolution

For forked-locals, Reveal in Finder/Terminal, Open in…, Copy as Pathname, and the Path field all target installed_from.source (the editable working tree), not the YNH install slot. Single canonical "where this lives on disk."

Sheet first-paint fix

All six sheets (Fork, Update, Duplicate, Add Marketplace, Session Recovery, Install) now apply .frame() at the .sheet content closure rather than inside the sheet body. Eliminates the rounded-rect placeholder that flashed before content resolved — a long-standing issue caused by NSWindow racing the SwiftUI layout pass on switch-based bodies.

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Coordinated YNH changes (already merged)

YNH change	Why TermQ needs it
Structured-output envelope (capabilities, ynh_version, --check-updates fields)	Capability gating + drift detection
installed_from.forked_from provenance	Forked-local source badge
ynh fork self-registers via pointer model	Single-call fork; live-edit workflow
ynh fork --name flag	Single-call Duplicate
Plugin-only update (ynh update <selfcontained>)	Drift on harnesses with no includes (gitflow case)
Tolerant null arrays in error rows	Documented; TermQ also defensive

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Testing

• Quality gate clean from swift package clean baseline — 1593 tests pass (17 pre-existing skips), 0 failures, 0 lint violations, format clean.
• End-to-end manual — Fork registry → editable copy. Edit .ynh-plugin/plugin.json description in source tree. Refresh. Detail pane shows the change without reinstall step. Uninstall preserves source tree on disk.
• Drift round-trip — manufacture drift in installed.json, refresh, click Update from warning banner, drift clears.

Manual checklist sits in .claude/sessions/manual-test-checklist.md (gitignored).

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Out of scope (queued for follow-ups)

• Inline include editor on the detail pane — backend (HarnessAuthor, marketplace include picker) is in place; UI not wired. Next focused branch.
• Phase 1.5 — Delegate editor — waits on ynh delegate add/remove/update.
• Phase 2 — Tools menu (Validate / Lint / Format / Preview / Diff vendors / Export / Migrate). YND-driven, no YNH coordination needed.
• Phase 3 — LLM authoring (Compress / Inspect / Create).

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Commit shape

Three logical commits:

1. feat(harness) — code (foundation, detail pane, fork & duplicate, drift detection, sheet sizing, tolerant decoder, action menus, editable path).
2. feat(localization) — 40 languages translated for the new UI surface.
3. test(harness) — coverage for fork, badges, decoder, drift signals.

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