Prototype proximity-gated local surface continuity

[Nocehi]

Scope

Replace the rejected long-distance rail→switcher goo experiment with a narrower presentation prototype: only genuinely local source→surface relationships may read as continuous. dsh-rice must not manufacture a tentacle across the interface.

The ordinary geometry gate is one application-rail width: 56px edge-to-edge.

What this now experiments with

1. Stable accessible source→target relations

The core src/surface-morph.js path remains standards-first:

• [aria-controls][aria-expanded] → visible controlled target;
• native <details><summary> → opened content;
• closest-edge geometry rather than center-to-center travel;
• one pointer-inert bridge only when the measured edge gap is <= 56px;
• RAF settling + ResizeObserver + mutation/scroll/resize refresh;
• normal hover/focus/open/release semantics, with reduced-motion presentation suppressed.

This is the preferred path for Todo/collapsed-card style disclosures. If the live host does not expose a durable accessible relationship, rice stays silent rather than guessing a private class/React seam.

2. Newly-visible nearby semantic popups

src/surface-morph-candidates.js adds a second standards-based candidate path for controls whose popup semantics live on the newly-mounted surface rather than on aria-controls:

• capture a recent compact button, [role=button], or [aria-haspopup] activation;
• snapshot semantic popup surfaces already visible before activation;
• for the next 18 animation frames, consider only newly-visible role=menu, role=listbox, role=dialog, or open native popover surfaces;
• connect only the nearest candidate within the same 56px edge-gap limit;
• keep the connector pointer-inert and release it when the popup disappears or leaves the locality gate.

This is intended to dogfood nearby composer action menus/pickers and the dsh-better-sidebar tab-bar + menu without adding a private selector map.

3. dsh-better-sidebar right-workbench corner bloom

The sidebar target here is specifically omdsh-dev/DSH-better-sidebar, while all implementation remains in dsh-rice.

The public betterSidebar client service is authoritative: rice injects it, reads getSnapshot().state, and subscribes with subscribeState(). Existing root hooks still mirror public side/bottom/open/size/maximize state.

The new candidate adapter adds a visual experiment for the right workbench only without querying any Better Sidebar CSS-module class:

• remember a fresh compact activation only inside the top-right 112px corner;
• require a subsequent public-service panelOpen transition within the freshness window to prove that activation belonged to the right workbench toggle;
• obtain panel width from public service state;
• play a 180ms local corner bloom from the toggle-sized source into a small top-right patch of the real right workbench, then fade out;
• closing runs the same geometry in reverse when a fresh top-right activation precedes panelOpen: true → false;
• prefers-reduced-motion: reduce suppresses the bloom;
• the bloom is pointer-events:none, aria-hidden, and never replaces the real workbench DOM.

The bottom workbench deliberately does not get this bloom: its top-right toggle and bottom destination are spatially non-local and would recreate the rejected tentacle topology.

There is no .dsh-better-sidebar selector, CSS-module substring match, vendored implementation, or modification to the Better Sidebar repository.

Todo / Produced / composer / collapsed-card dogfood paths

• Todo / collapsed card: use the stable accessible-relation path when the live DSH build exposes one; otherwise remain untouched.
• Composer: a nearby newly-mounted semantic menu/listbox/dialog/popover may get the short <=56px bridge.
• Produced: current dsh-better-sidebar owns a produced-files interception whose chips open the editor through public betterSidebar.openTab(...). This is intentionally a locality negative/conditional test: if the real destination is far across the conversation viewport, rice should draw nothing rather than force a cross-viewport transition.
• Better Sidebar tab +: if the DSH Menu surface mounts semantically and within 56px, it should get only the tiny local bridge.

Acceptance / dogfood questions

• Does the right-workbench toggle read as a short corner bloom on open and reverse on close, never as a tether or emitted object?
• Does the 180ms bloom disappear into the real panel quickly enough that recognition and interaction remain immediate?
• Does the Better Sidebar tab + menu get a tiny local connector when its real semantic menu is nearby, and release cleanly on close?
• Do nearby composer menus/pickers participate only when a new semantic surface actually appears within 56px?
• Do Todo/collapsed-card relations work only where the host exposes the stable accessible relation?
• Does Produced correctly remain animation-free when its real editor destination is non-local?
• Are side/bottom/split, resize, maximize, session switching, keyboard activation, reduced motion, focus, and hit targets behaviorally unchanged?

Implementation boundary

No new runtime package is added. src/surface-morph.js and src/surface-morph-candidates.js remain dependency-free scripts concatenated into the existing browser artifact; the generated client still allows only the existing React and DSH UI-primitives requires.

Focused tests cover the 56px locality gate, semantic popup discovery, observer lifecycle, Better Sidebar public-service gating, top-right locality/freshness, 180ms reversible bloom, reduced motion, pointer-inert presentation, absence of private sidebar selectors, and build purity.

Exact-head CI on dda1f9227f96837bbf492c5fd7c8657346d94b90 is green (check run #199). Physical dogfood remains the visual merge gate.