feat(horseshoe): add 12px void gap between chat and profile pane with rounded TL/BL on profile, drop page-nav right rounding

src/app/components/page/Page.tsx

@@ -62,28 +62,12 @@ export function PageRoot({ nav, children }: PageRootProps) {
   if (horseshoe) {
     return (
       <Box grow="Yes" className={ContainerColor({ variant: 'Background' })}>
-        {/* Page-nav slot — paints two void squares at its top-right and
-            bottom-right via `background-image` (the
-            `linear-gradient(SAME, SAME)` idiom = a solid-colour image).
-            The wrapper's bg sits naturally beneath its in-flow
-            children, so PageNavHeader and the bottom row paint their
-            normal Background colour over the void everywhere except in
-            their own rounded TR / BR carves — which expose the void.
-            No absolute positioning, no z-index gymnastics, and the
-            resize handle inside `ResizablePageNav` stays a sibling of
-            the clipped inner column so it isn't clipped. */}
-        <Box
-          shrink="No"
-          style={{
-            display: 'flex',
-            backgroundImage: `linear-gradient(${VOJO_HORSESHOE_VOID_COLOR}, ${VOJO_HORSESHOE_VOID_COLOR}), linear-gradient(${VOJO_HORSESHOE_VOID_COLOR}, ${VOJO_HORSESHOE_VOID_COLOR})`,
-            backgroundSize: `${horseshoeRadius} ${horseshoeRadius}, ${horseshoeRadius} ${horseshoeRadius}`,
-            backgroundPosition: 'top right, bottom right',
-            backgroundRepeat: 'no-repeat, no-repeat',
-          }}
-        >
-          {nav}
-        </Box>
+        {/* Page-nav slot — its right edge stays square (the original
+            TR / BR rounding was reverted). The 12px void gap below
+            still creates a visible seam between page-nav and the chat
+            panel, and the resize handle inside `ResizablePageNav` is
+            shifted into that void via the inline style below. */}
+        {nav}
         <Box
           shrink="No"
           style={{

src/app/components/page/style.css.ts

@@ -1,7 +1,6 @@
 import { style } from '@vanilla-extract/css';
 import { recipe, RecipeVariants } from '@vanilla-extract/recipes';
 import { DefaultReset, color, config, toRem } from 'folds';
-import { VOJO_HORSESHOE_RADIUS_PX } from '../../styles/horseshoe';
 
 export const PageNavResizable = style({
   position: 'relative',
@@ -89,20 +88,16 @@ export const PageNav = recipe({
 export type PageNavVariants = RecipeVariants<typeof PageNav>;
 
 // Web-only horseshoe shell wrapping every page-nav's inner column.
-// `overflow:hidden + border-radius` clips the nav's content into a
-// shape with rounded TR and BR corners; the wrapper PageRoot puts
-// behind the nav paints `#090909` at those same corners via background-
-// image, so the carved area reads as the horseshoe void. An explicit
-// `Background.Container` bg is required: folds `<Header>` is fully
-// transparent (it only sets color/border), and some routes (Bots,
-// Channels) don't paint anything at the bottom — without this bg the
-// PageRoot void would bleed through the entire header / footer instead
-// of just the carved corner. Applied conditionally in `PageNav` /
-// `ResizablePageNav` below; native skips it entirely.
+// Previously carved rounded TR / BR corners against a void backdrop;
+// the rounding was reverted while keeping the 12px void gap between
+// page-nav and chat panel, so this class now just enforces an opaque
+// Background bg + clips overflow. The bg keeps the page-nav header /
+// footer painted even on routes (Bots, Channels) that don't paint
+// anything of their own; `overflow:hidden` is defensive against any
+// child that might bleed past the inner column. Applied conditionally
+// in `PageNav` / `ResizablePageNav` below; native skips it entirely.
 export const PageNavInnerWebHorseshoe = style({
   overflow: 'hidden',
-  borderTopRightRadius: toRem(VOJO_HORSESHOE_RADIUS_PX),
-  borderBottomRightRadius: toRem(VOJO_HORSESHOE_RADIUS_PX),
   backgroundColor: color.Background.Container,
 });
 

src/app/features/room/Room.tsx

@@ -1,9 +1,12 @@
 import React, { useCallback } from 'react';
-import { Box, Line } from 'folds';
+import { Box, Line, toRem } from 'folds';
 import { useMatch, useParams } from 'react-router-dom';
 import { isKeyHotkey } from 'is-hotkey';
 import { useAtomValue } from 'jotai';
 import { RoomView } from './RoomView';
+import { userRoomProfileAtom } from '../../state/userRoomProfile';
+import { ContainerColor } from '../../styles/ContainerColor.css';
+import { VOJO_HORSESHOE_GAP_PX, VOJO_HORSESHOE_VOID_COLOR } from '../../styles/horseshoe';
 import { MembersDrawer } from './MembersDrawer';
 import { ThreadDrawer } from './ThreadDrawer';
 import { ScreenSize, useScreenSizeContext } from '../../hooks/useScreenSize';
@@ -91,6 +94,24 @@ export function Room({ renderRoomView }: RoomProps) {
 
   const unreadThreadingEnabled = useUnreadThreadingEnabled();
 
+  // Profile horseshoe: when the right-side profile pane is open on
+  // desktop/tablet, paint a 12px void seam between the chat column and
+  // the profile, and carve rounded TL/BL corners on the profile pane.
+  // The chat column itself keeps a straight right edge (no rounding) —
+  // only the profile carves, so the void gap reads as one black bar
+  // with a single rounded contour on the right side of the seam.
+  // Mirrors the page-nav <-> chat split from PageRoot (commit 363bd9d)
+  // minus the chat-side rounding. Mobile and the thread-drawer case
+  // don't mount the side pane, so the wrap is gated on both.
+  //
+  // Void colour is painted on the parent flex row (covering everything
+  // not painted by an opaque child) so the profile pane's TL/BL carves
+  // expose void rather than the chat-panel-inner's Background from
+  // PageRoot. The chat column applies an explicit Background bg so the
+  // parent void can't bleed through any transparent slivers.
+  const profileOpen = !!useAtomValue(userRoomProfileAtom);
+  const showProfileHorseshoe = profileOpen && !isMobile && !showThreadDrawer;
+
   useKeyDown(
     window,
     useCallback(
@@ -120,9 +141,22 @@ export function Room({ renderRoomView }: RoomProps) {
   return (
     <PowerLevelsContextProvider value={powerLevels}>
       <ThreadDrawerOpenProvider value={showThreadDrawer}>
-        <Box grow="Yes">
+        <Box
+          grow="Yes"
+          style={
+            showProfileHorseshoe
+              ? { backgroundColor: VOJO_HORSESHOE_VOID_COLOR }
+              : undefined
+          }
+        >
           {callView && (screenSize === ScreenSize.Desktop || !chat) && (
-            <Box grow="Yes" direction="Column">
+            <Box
+              grow="Yes"
+              direction="Column"
+              className={
+                showProfileHorseshoe ? ContainerColor({ variant: 'Background' }) : undefined
+              }
+            >
               <RoomViewProfilePanel header={<RoomViewHeader callView />}>
                 <Box grow="Yes">
                   <CallView />
@@ -131,7 +165,13 @@ export function Room({ renderRoomView }: RoomProps) {
             </Box>
           )}
           {!callView && !drawerHidesChat && (
-            <Box grow="Yes" direction="Column">
+            <Box
+              grow="Yes"
+              direction="Column"
+              className={
+                showProfileHorseshoe ? ContainerColor({ variant: 'Background' }) : undefined
+              }
+            >
               <RoomViewProfilePanel header={<RoomViewHeader />}>
                 <Box grow="Yes">
                   {renderRoomView?.({ eventId }) ?? <RoomView eventId={eventId} />}
@@ -143,8 +183,23 @@ export function Room({ renderRoomView }: RoomProps) {
         {/* Tablet / Desktop: profile renders as a third pane to the
             right of the chat. Mobile uses the top horseshoe inside
               `RoomViewProfilePanel`, so we don't mount the side pane
-              there. */}
-          {!isMobile && !showThreadDrawer && <RoomViewProfileSidePanel />}
+              there. The 12px void gap (same as page-nav <-> chat split
+              from PageRoot) sits between the chat column and the pane
+              so the seam reads identically to the rest of the app. */}
+          {!isMobile && !showThreadDrawer && (
+            <>
+              {showProfileHorseshoe && (
+                <Box
+                  shrink="No"
+                  style={{
+                    width: toRem(VOJO_HORSESHOE_GAP_PX),
+                    backgroundColor: VOJO_HORSESHOE_VOID_COLOR,
+                  }}
+                />
+              )}
+              <RoomViewProfileSidePanel />
+            </>
+          )}
 
           {callView && chat && (
             <>

src/app/features/room/RoomViewProfileSidePanel.css.ts

@@ -1,18 +1,28 @@
 import { style } from '@vanilla-extract/css';
 import { color, config, toRem } from 'folds';
+import { VOJO_HORSESHOE_RADIUS_PX } from '../../styles/horseshoe';
 
 // Right-side profile pane sized like the members drawer family —
 // wide enough for the identity card + chips without dominating the
 // chat. Clamp keeps it readable on narrow desktops and prevents
 // runaway width on ultra-wide displays.
+//
+// Left edge is rounded (TL + BL) to mirror the chat column's TR / BR
+// carves across the 12px horseshoe void gap rendered by Room.tsx —
+// same design language as the page-nav <-> chat split. `overflow:
+// hidden` keeps the rounded corners clean against the header /
+// scroll content; the void colour beneath is painted by the parent
+// flex row, not by the panel itself.
 export const panel = style({
   flexShrink: 0,
   width: `clamp(${toRem(300)}, 25%, ${toRem(380)})`,
   display: 'flex',
   flexDirection: 'column',
   backgroundColor: color.Surface.Container,
-  borderLeft: `${config.borderWidth.B300} solid ${color.Surface.ContainerLine}`,
   minHeight: 0,
+  overflow: 'hidden',
+  borderTopLeftRadius: toRem(VOJO_HORSESHOE_RADIUS_PX),
+  borderBottomLeftRadius: toRem(VOJO_HORSESHOE_RADIUS_PX),
 });
 
 // Match the chat header's left gutter (RoomViewHeaderDm uses S200