Resolves #15008

Related: #14616 — the live-instance identity remainder stays OPEN (its ACs bind stable componentRef to the SAME live pane instance across projection per the docking design's pane contract; the reviewer's exact-head falsifier proved this PR's switch rebuilds instances, so that contract is deliberately NOT claimed here — its owner drives it as the adapter-tier successor).

The cockpit's named duty layouts — Fleet / Focus / Review — switching the committed dock document through the SAME commit loop every other dock gesture uses. The preset library is a DockPerspectiveStore over a seeded dockLayoutCollection.v1 (workspace-scope captures — the landed wrapper; the multi-window dockPerspective.v1 topology tier is explicitly NOT this scope per the settled spec's two-scope table). A switch is loadPerspective (the landed fail-closed restore: validate everything before mutating anything) feeding onDockZoneDocumentChange — so the transition re-projects FLIP-animated exactly like a splitter commit, and reduced-motion collapses through the token layer by construction, not per call site.

Scope honesty (converged in review): what ships here is the state-backed preset layer over today's rebuild-model projection — pane instances are destroyed/recreated by the switch (the reviewer's live falsifier confirmed it), with continuity delivered at the STATE tier: a switch touches only the layout SSOT, owner-held pane state (gridAdapterState / streamEvents) survives untouched, the next re-materialization carries it, and the provider-owned roster store never restarts (fixture-asserted). The instance-identity tier — the same live instance moved, never destroyed — is #14616's remainder, not claimed by this PR.

Fail-closed is VISIBLE: a refused switch (unknown name; any validator refusal) leaves the live document byte-identical, records presetError on the owner, and re-renders the control bar with an error chip — a refusal can never look like a silent no-op. The store's whole-candidate validation covers the deep corrupt-record class upstream (its own falsifier suite).

The bar: one button per stored perspective (pressed follows activeLayoutId), derived from store state on every rebuild — the post-switch re-projection updates pressed states for free. The perspectives rail pane keeps its honest placeholder: the fuller management surface (save-current / rename / delete UI) is the switcher leaf's scope, not this one's.

Evidence: L3 (real preset-button click committing the Focus document on the mounted cockpit + NL-driven activatePerspective switching Review/Fleet + the fail-closed ghost refusal with worker truth intact — plus the full agentos e2e suite) → L3 required (the AC names NL-verifiable switching verbatim). Residual: the post-switch BAR re-render's DOM flush rides the open wholesale-refresh reconciliation defect like every re-projection on this surface (worker truth + one live-bar gesture fully proven; the journey drives subsequent switches through the NL seam by design).

Deltas from ticket

• The close-target converged in review: this PR delivers the state-backed layer under #15008 (its honest scope); #14616's instance-identity contract stays open as its owner's remainder — the review record on this PR carries the full reasoning.
• The originally-cited blocked-by on the source ticket predated its own blocker's closure (the perspective-semantics spec settled 2026-07-02; the store ships its §2 semantics) — recorded at intake as satisfied, not bypassed.
• The preset bar lives in the cockpit control bar (operable-cold, always visible) rather than behind the auto-hidden rail pane — a hidden switcher would defeat the "operator switches instead of hand-dragging" premise.

Test Evidence

At head 5c7fcd580:

npm run test-unit -- test/playwright/unit/apps/agentos/ --workers=1
197 passed / 1 failed — the red is fleetGrid.spec.mjs:103, the PRE-EXISTING sweep-order heap-bleed (convicted on clean dev; repro triple in PR #14996's body; its owner has the flag)

NEO_E2E_PORT=8117 npx playwright test agentos -c test/playwright/playwright.config.e2e.mjs --workers=1
6 passed — the FULL agentos e2e suite, including the new perspective journey (real Focus click → worker-verified commit; NL Review/Fleet switches; ghost refusal fail-closed) and every sibling surface

The four new unit specs: the seeded library validates whole + lists the three duty presets; a switch restores through the standard commit loop (stored synchronously, re-projected deferred, active record tracked); state continuity across a switch (owner-held fields + resolver output + the library untouched); the refused switch fails closed visibly (byte-identical document, error chip rendered, pressed states derived from store state).

Post-Merge Validation

• When the wholesale-refresh reconciliation defect closes, extend the journey with the bounded-frame DOM-convergence poll (the witness shape its owner confirmed) covering the post-switch bar + pane flush.
• The switcher leaf (save-current / rename / delete management UI) replaces the perspectives rail placeholder and consumes the same store seam.

Process note: authored during the operator-granted temporary Fable 5 window.

Authored by Grace (Claude Fable 5, Claude Code). Session ef6b9a4a-54ec-4afb-8438-f89a3ee46ad2