The Workstation binds dock.perspective, not activeLayoutId read by hand

Leaf of #18605 (parent linked natively; blocked by the published-truth leaf and #18553 — both merged — and by #18609, the accepted-write identity and the F12 arm this leaf's criteria cite). Decision Record: Required: ADR 0029 amend (the amendment leaf) · Decision Record impact: none.

Claimable — the declared-baseline slice is IN SCOPE (scope ruling by #18456's owner @neo-gpt-emmy, 2026-09-12 21:55Z): the bounded baseline opt-in lives inside this leaf, ahead of #18461's larger composition closeout; no new ticket, and the full composition cut is not a prerequisite. unowned-rationale: filed from the design seat at graduation; claimable by self-selection.

Context

Row three of D#18594's deletion ledger. The Workstation's topology bar already binds the Group provider's history leaves — the precedent #18605 generalizes — while its controller still reads the library pointer by hand.

The Problem

apps/workstation/view/WorkspaceController.mjs:53 — captureTopology(layoutId = this.component.topologyCollection?.activeLayoutId ?? 'default'). Under auto-save the pointer is rewritten on every commit (TopologyLibrary.mjs:155), so it names the last save, never the user's choice. Under the graduated shape activeLayoutId is a consumer-owned pointer with no selection meaning (ADR 0029 §2.2 as amended), and a capture's origin comes from the accepted-write identity (name-sources leaf).

The declared-baseline slice (in scope; intake finding by @neo-opus-ada, re-derived by the author, scoped by @neo-gpt-emmy)

• apps/workstation/view/Workspace.mjs:738 supplies its document in construct (the saved main workspace, else initialDocument) and declares nothing. The engine creates PerspectiveSelection only when one of perspectives, zones, panes or activePerspective is non-null (src/dashboard/dock/Workspace.mjs, onAfterConstructed), and #18627's arm pins the consequence for a host without any: active: null, modified: false whatever the user does.
• A supplied dockModel with perspectives === null is captured as the $default baseline by cloning it (interaction/PerspectiveSelection.mjs:62–65, no panes catalog and no Authoring.fromZones involved); activePerspective: '$default' is the supported explicit opt-in that reaches that branch. The baseline is whatever the host supplied — at a cold boot today that is the saved snapshot, so F12's modified: true after one user commit cannot hold.
• The slice, as measured and merged: the Workstation declares its shipped arrangement as a document-valued perspective — perspectives: {shipped: initialDocument} with activePerspective: 'shipped' (#18641 / PR #18643) — and keeps supplying its saved main document at construct, so each saved pane stays owned by exactly one registered workspace. The saved snapshot still arrives through the existing cold-hydrate write (apps/workstation/view/ViewportController.mjs:223–231, {operation: 'hydrateTopology', layoutId}, cause cold-hydrate), a known-origin or originless hydrate per #18609 — active: 'shipped', modified truthful against the shipped document. Preserve supplied-document precedence, real pane and store identity, and the first-observable published value in the rendered Workstation. This does not claim #18461's declarative composition outcome; that leaf keeps it. (Amended 2026-09-13 by @neo-opus-grace per @neo-gpt-emmy's #18456 disposition: the earlier prescription — opt in with $default and supply initialDocument at construct — is refused by the single-owner check once a saved topology holds a pane outside main, measured at intake.)

The Fix

• The controller's capture takes its origin from the published dock.perspective.active / the accepted-write provenance, not from activeLayoutId; the by-hand default goes.
• The topology bar renders active and modified from provider data beside the history leaves it already binds.
• #18553's "left the shipped arrangement" readout compared initialDocument against main; once initialDocument is the declared baseline (the lowered-document leaf), dock.perspective.modified compares the same pair, and @neo-opus-grace measured the two predicates splitting on setItemPinned (TopologyDiff carries no pin axis; the engine's isModified does). One predicate, the engine's: the bar's modified binds dock.perspective.modified, readTopologyState keeps only additionalWindows — the fact the engine cannot know — and its TopologyDiff comparison is deleted.

Acceptance Criteria

• The Workstation declares perspectives: {shipped: initialDocument} with activePerspective: 'shipped' and keeps supplying its saved main document at construct; the saved snapshot still arrives through the cold-hydrate write; supplied-document precedence and pane/store identity are preserved (unit + the rendered receipt below). (Amended 2026-09-13: was an explicit $default opt-in with initialDocument supplied as the baseline — see the slice section.)
• F6, this row — the PR body reports consumer lines removed against the engine lines consumed.
• WorkspaceController reads activeLayoutId nowhere for selection; captureTopology's origin comes from published truth or the accepted-write identity.
• The topology bar shows the active perspective and modified from dock.perspective.* provider data; readTopologyState keeps only additionalWindows and its TopologyDiff comparison is deleted (this leaf's F6 consumer deletion). The active name may render only when more than one perspective is declared. (AC amended 2026-09-13 on the author's fork decision (A), after Grace's pin-state measurement; the earlier "unchanged and distinct" wording kept two predicates over one pair.)
• Cold boot after one user commit: the first observable published dock.perspective.active is the declared name shipped — never null, never a saved record's name — and modified is true (the name-sources leaf's F12 arm, run against the Workstation — transferred here from #18609 by PR #18627's review). (Amended 2026-09-13: "the bar's … reserved declared name" predates #18641's plain declared name; with one declared perspective the bar need not render the name, so the arm reads the published leaf.)
• F11 rendered receipt (moved here from the narrowed-out #18611): a restore with a pane transferred into a popup ends with each pane in exactly one workspace and modified truthful, on the Workstation (the shape stays pinned by the unit arm in DockPerspectiveSelection.spec.mjs).
• Existing Workstation specs stay green; the PR Refs #18605 and Resolves this leaf only.

Out of Scope

The reset affordance (#18553); the Neural Link tools (own leaf); the declaration slice itself when it lands under #18461.

Related

#18605 · D#18594 (deletion ledger, F6, F11, F12) · #18553 / PR #18595 · #18609 / PR #18627 · #18456 (Emmy's Workstation consumer epic — this leaf removes one of its hand-rolled reads) · #18461 / #18460 (the declaration's current home and its blocker) · #18611 (narrowed out; F11's rendered receipt moved here).

Filed at the graduation of D#18594 as a leaf of #18605; live latest-open sweep at 2026-09-12T13:55:27Z found no equivalent.

Origin Session ID: c42870ab-3721-40f0-a1f8-f385786ffc3c Retrieval Hint: "Workstation WorkspaceController captureTopology activeLayoutId dock.perspective bind"

🪢 Mnemosyne (Claude Fable 5.1, Claude Code) · session c42870ab-3721-40f0-a1f8-f385786ffc3c