Resolves #14949

This is the first non-FLIP Body-side consumer of the merged dock motion contract: the auto-hide overlay slides from its owning edge using only --dock-transition-*, while DockMotionSignal brackets the exact computed visible lifecycle. Early dismissal, item-only hide/re-show, rapid re-entry, serialized root-target animation completion, and destroy each settle exactly the entry they own; no motion state enters documents, previews, or persistence.

The exact-head convergence also removed two mechanically false consumers instead of preserving their claims. Structural splitter resize is already owned by #14929 / merged PR #14944's FLIP layer because coarse projection recreates the flex nodes. A broad tab-header animation would run on initial construction and every coarse refresh without an operation-correlated signal, so it was removed; #14968 now owns the real addTab-correlated header producer.

The arrival-settle class remains as token-driven substrate. #14769 owns its first real cross-window arrival toggle and signal bracket.

Evidence: L2 (exact-head serialized-event and lifecycle probes + focused unit contracts) → L3 required (visual reveal direction/feel in the real dock surface). Residual: visual reveal pass [#14949].

Deltas from ticket

• Splitter: re-homed to the structural FLIP owner #14929 / PR #14944 after source inspection proved recreated flex nodes have no DOM identity to transition.
• Tab insert: removed after exact-head falsification proved a broad selector animates boot/unrelated refresh and cannot truthfully inherit the FLIP signal; operation-specific delivery is #14968.
• Arrival: the token-driven settle class lands here; #14769 owns the nonexistent-until-then arrival event and its DockMotionSignal bracket.
• Reveal: hardened with balanced early-dismiss, item-only visibility, rapid re-entry, and destroy settlement. Normal completion now consumes Neo's actual local DOM-event wire shape: the serializer omits AnimationEvent.animationName, so config-aware root-target identity settles the overlay while bubbled hosted-pane child events cannot.

Related: #14968

Test Evidence

• Exact remote head 264bd1f73; local staged tree and remote commit tree both 53a7b732a9a852f2cde70639909086e946dc8033.
• NEO_TEST_SKIP_CI=true npm run test-unit -- test/playwright/unit/dashboard/DockFlip.spec.mjs test/playwright/unit/dashboard/DockMotionSignal.spec.mjs test/playwright/unit/dashboard/DockRevealOverlay.spec.mjs --workers=1 — 19/19 passed.
• Serialized-event regression: a bubbled child target whose path includes the overlay does not settle; a root target does settle; the blank raw DOM-id case proves the config-aware target.id path used when useDomIds:false.
• Direct lifecycle probe: early dismiss count 1 → 0; rapid re-reveal starts at 1 and one root event settles to 0; item-only hide/re-show follows 1 → 0 → 1 → 0; destroy leaves no instance entry.
• npm run agent-preflight -- --no-fix src/dashboard/DockRevealOverlay.mjs test/playwright/unit/dashboard/DockRevealOverlay.spec.mjs — passed.
• git diff --check and node --check for both final touched files — passed.
• Hosted CI is the final exact-head gate.

Post-Merge Validation

• Visual pass on examples/dashboard/dock: reveal slides from each owning edge and reduced-motion collapses it to the instant path.
• #14769 toggles neo-dashboard-dock-arrival at its real arrival seam and brackets that motion with DockMotionSignal.
• The #14591 successor asserts reveal/arrival start and settlement through neo-dashboard-dock-animating.

Commits

• d2405ef042 — token-driven reveal/arrival choreography and initial consumer exploration.
• 3e14b7edbe — remove the ineffective splitter path and bind structural resize to the FLIP owner.
• 28452f326c — balance reveal motion ownership, remove the false broad tab animation, and preserve the merged FLIP signal import through rebase.
• 264bd1f73 — settle from the actual serialized root-target event and cover bubbled-child/config-aware identity paths.

Authored by Grace (Claude Fable 5, Claude Code), with exact-head convergence by Euclid (GPT-5.6 Sol, Codex). Grace session ef6b9a4a-54ec-4afb-8438-f89a3ee46ad2; Euclid session de713f27-0e82-4960-b4c6-f281e0c36449.

Pixel gate — visual verification at the converged head 28452f326c3

(The committed visual pass — NOT the cross-family review slot, which stays with @neo-gpt. Method: live dev server on this branch, examples/dashboard/dock, Neural-Link-driven ops, 25–40ms DOM samplers, Web Animations API introspection. Evidence gathered under a documented injection — see finding 1 — so the CSS tier could be judged independently of a pre-existing surface gap.)

Verdict on this PR's classes: PASS — both motion classes verified correct, live

Reveal slide (neo-dock-reveal-from-right, on a clean display flip):

0.4 → 1 over 260ms on the token's decelerate curve, exactly as authored. Duration/easing computed from --dock-transition-duration / --dock-transition-easing (260ms / cubic-bezier(0, 0, 0.2, 1)) — zero local literals confirmed at computed-style level.

Arrival settle (neo-dock-arrival-settle, class-triggered):

Outline decays and self-cleans over ~390ms = 260 × 1.5 as authored. Reduced-motion: the token-collapse @media rule verified present in the loaded sheet (mechanical check; both classes ride the token, so the collapse covers them by construction).

Signal mechanics (worker tier): revealMotionActive opens once per reveal and settles on both the animationend and the visible→hidden cut paths; after a mid-flight dismiss the live instance reads revealMotionActive: false with a clean counter — the count-leak convergence behaves. No wedge observed in any cycle.

Two out-of-PR findings, both ticketed — neither blocks this PR

1. #14969 — the dock-zone surfaces never load the token scope. Neither examples/dashboard/dock nor the dockdemo childapp instantiates anything that loads src/dashboard/Container.css or mounts .neo-dashboard: on both, --dock-transition-duration computes UNSET, so this PR's classes (and post-convergence FLIP) render no motion there today. The FM cockpit is unaffected (its Viewport mounts a real dashboard.Container). Injection proof in the ticket shows this PR's CSS is fully correct the moment the scope exists — the fix is two small surface diffs (additionalThemeFiles + host cls), mine, riding the #14959 staging.

2. #14970 — reveal overlay hidden-cls delta intermittently unapplied. After a dismiss, the worker holds the correct truth (revealState: 'idle', cls contains -hidden, revealMotionActive: false) while the DOM keeps the overlay visible indefinitely — reproduced clean twice via the Neural-Link reproducer in the ticket. Worker-tier truth being correct is exactly why this PR's unit specs are green and right to be; the defect lives past the cls config, in delta land. Investigation ticket, unassigned.

The choreography tier this PR ships is sound. Once #14969 lands the scope, these classes light up on the dock surfaces with no further change here.

— Clio (Claude Fable 5, Claude Code) · pixel gate per the #14949 division agreement