fix(timeline): your own new message always scrolls into view (#212)

Auto-scroll on a live event only ran while the at-bottom flag was true, so a
stale flag (in-place growth like a poll gaining a row briefly pushes the anchor
out of view; or simply having scrolled up) left your own just-sent message
below the fold behind 'Jump to Latest'. An own non-relation, non-state,
non-reaction event now always brings the live end into view: advance the
range + smooth scroll when the window is at the live end, otherwise reset to
the live timeline like the Jump to Latest button. Others' messages keep the
current behaviour.

Verified headless: scrolled up 600 px → Send → message visible, no Jump pill
(before: Jump pill, message off-screen).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/room/RoomTimeline.tsx

@@ -705,6 +705,34 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
           }));
           return;
         }
+        // [Gitea #212] Your OWN new message always comes into view — that is
+        // what pressing Send means — even if the at-bottom flag went stale
+        // (in-place growth like a poll gaining a row briefly pushes the anchor
+        // out of the viewport) or you had scrolled up to read.
+        const ownNewMessage =
+          mEvt.getSender() === mx.getUserId() &&
+          !mEvt.isRelation() &&
+          !mEvt.isRedaction() &&
+          !mEvt.isState() &&
+          mEvt.getType() !== MessageEvent.Reaction;
+        if (ownNewMessage) {
+          if (atLiveEndRef.current) {
+            setAtBottom(true);
+            scrollToBottomRef.current.count += 1;
+            scrollToBottomRef.current.smooth = true;
+            setTimeline((ct) => ({
+              ...ct,
+              range: { start: ct.range.start + 1, end: ct.range.end + 1 },
+            }));
+          } else {
+            // Paginated back into history: jump to the live end like the
+            // "Jump to Latest" button does.
+            setTimeline(getInitialTimeline(room));
+            scrollToBottomRef.current.count += 1;
+            scrollToBottomRef.current.smooth = false;
+          }
+          return;
+        }
         setTimeline((ct) => ({ ...ct }));
         if (!unreadInfo) {
           setUnreadInfo(getRoomUnreadInfo(room));