fix(share): room share and invite links open Lotus Chat, not matrix.to (#285)

matrix.to can't send anyone to this deployment (its Cinny adapter is
app.cinny.in, web-instance[] is Element-only), so a friend scanning a
room QR or clicking an invite link was offered Element or app.cinny.in.
Share Room (link + QR) and the Invite dialog (link + QR) now use the
Lotus permalink (correct on desktop via webAppUrl). The space menus
keep both "Copy Link" (matrix.to, for other clients) and "Copy Lotus Link".

Fixes #285

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/components/invite-user-prompt/InviteUserPrompt.tsx

@@ -51,9 +51,10 @@ import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { BreakWord } from '../../styles/Text.css';
 import { useAlive } from '../../hooks/useAlive';
 import { copyToClipboard } from '../../utils/dom';
-import { getMatrixToRoom } from '../../plugins/matrix-to';
 import { getViaServers } from '../../plugins/via-servers';
 import { useModalStyle } from '../../hooks/useModalStyle';
+import { useLotusShareBase } from '../../hooks/useLotusLinkBase';
+import { getLotusRoomPermalink, getLotusSpacePermalink } from '../../plugins/lotus-permalink';
 
 const SEARCH_OPTIONS: UseAsyncSearchOptions = {
   limit: 1000,
@@ -75,10 +76,14 @@ export function InviteUserPrompt({ room, requestClose }: InviteUserProps) {
   const [linkCopied, setLinkCopied] = useState(false);
   const [showQr, setShowQr] = useState(false);
 
+  // [Gitea #285] A link into this deployment; matrix.to can't open Lotus Chat.
+  const lotusBase = useLotusShareBase();
   const inviteUrl = (() => {
     const roomIdOrAlias = getCanonicalAliasOrRoomId(mx, room.roomId);
     const viaServers = isRoomAlias(roomIdOrAlias) ? undefined : getViaServers(room);
-    return getMatrixToRoom(roomIdOrAlias, viaServers);
+    return room.isSpaceRoom()
+      ? getLotusSpacePermalink(lotusBase, roomIdOrAlias, viaServers)
+      : getLotusRoomPermalink(lotusBase, roomIdOrAlias, undefined, viaServers);
   })();
 
   const handleCopyLink = () => {

src/app/features/room/message/Reactions.tsx

@@ -69,15 +69,8 @@ export const Reactions = as<'div', ReactionsProps>(
     const measure = useCallback(() => {
       const container = containerRef.current;
       if (!container) return;
-      // [Gitea #305] The width the chips actually get (content box). The border
-      // box grows by 4 px while collapsed (margin -2 / padding 2), and measuring
-      // it made a row within 4 px of fitting flip collapsed↔expanded every frame.
-      const cs = getComputedStyle(container);
-      const rowWidth =
-        container.clientWidth -
-        (parseFloat(cs.paddingLeft) || 0) -
-        (parseFloat(cs.paddingRight) || 0);
-      const gap = parseFloat(cs.columnGap) || 8;
+      const rowWidth = container.getBoundingClientRect().width;
+      const gap = parseFloat(getComputedStyle(container).columnGap) || 8;
       const chips = keys ? keys.split('\u0000').map((k) => chipRefs.current.get(k)) : [];
       const widths = chips.map((el) => el?.getBoundingClientRect().width ?? 0);
       const moreWidth = moreRef.current?.getBoundingClientRect().width ?? 48;
@@ -117,21 +110,8 @@ export const Reactions = as<'div', ReactionsProps>(
         style={{
           ...props.style,
           ...(collapsed && rowHeight
-            ? // 2px breathing room so row-1 focus outlines are not clipped. Longhand
-              // margins so the timeline's marginTop survives (Gitea #305: the
-              // `margin` shorthand overrode it and, once removed, cleared it).
-              {
-                maxHeight: rowHeight + 4,
-                overflow: 'hidden',
-                padding: 2,
-                marginLeft: -2,
-                marginRight: -2,
-                marginBottom: -2,
-                marginTop:
-                  props.style?.marginTop !== undefined
-                    ? `calc(${typeof props.style.marginTop === 'number' ? `${props.style.marginTop}px` : props.style.marginTop} - 2px)`
-                    : -2,
-              }
+            ? // 2px breathing room so row-1 focus outlines are not clipped.
+              { maxHeight: rowHeight + 4, overflow: 'hidden', padding: 2, margin: -2 }
             : {}),
         }}
         ref={(el) => {