release #5516: composer-grow re-pin — hot-path optimization + CHANGELOG

Addresses Greptile P2 nit: autoResize() now only calls the re-pin when the
composer actually grew (offsetHeight before/after compare), skipping the DOM
read on a no-height-change keystroke. The #composerWrap ResizeObserver remains
the safety net for growth paths that bypass autoResize. Test tightened to assert
the grow-guard. CHANGELOG entry added (self-built, release owns changelog).

CHANGELOG.md

@@ -14,6 +14,7 @@
 
 ### Fixed
 
+- **The transcript no longer scrolls up when the composer grows.** When you were pinned to the bottom of a conversation and the composer got taller — multi-line typing, `Shift+Enter`, or a multi-line / dictation paste — the transcript viewport shrank by the same amount and left you stranded a row or two above the bottom (it read as the chat "randomly scrolling up" during normal use). The transcript now re-pins to the bottom whenever the composer grows, but only when you were genuinely still pinned there — if you'd scrolled up to read history, nothing yanks you back down. (#5516, #5514, #5515)
 - **A deleted conversation no longer comes back as a read-only "ghost" after a restart.** Deleting a WebUI session removed its file but left a recoverable row in the agent's state database, so after a server restart and page reload the deleted conversation could reappear as a read-only "Agent" session still showing its old transcript. Deleted WebUI sessions are now recorded in a durable tombstone that the sidebar projection, startup backup-recovery, audit, and session-claim paths all honor, so a deleted session stays gone (the backend keeps returning the 404 the client relies on to clear the stale route). Genuine crash recovery is unaffected — a session whose sidecar is lost without a delete is still restored — imported external-channel (messaging) sessions are exempt and keep their transcript, and a deleted id is automatically un-tombstoned if the same session is later re-created or re-imported. Thanks @rodboev. (#5504, #5498)
 - **A drag that ends over the sidebar no longer switches conversations by accident.** Releasing the mouse (a stray `pointerup`) over a session row after a drag that began elsewhere in the main content area could switch you into that conversation unintentionally. Session switching now ignores a `pointerup` that isn't a genuine click on the row. Thanks @webtecnica. (#5487, #5462)
 - **Extension gallery downloads no longer hang on networks with broken IPv6.** Gallery installs and registry fetches followed the OS address order (IPv6-first); on a network advertising dead IPv6 routes, every install stalled for the full TCP timeout before falling back to IPv4. Downloads now try IPv4 first (via a non-global, thread-safe per-connection override that preserves the existing redirect allowlist and timeouts), so installs are fast again on such networks. Thanks @rumotoshino. (#5458)

static/messages.js

@@ -6181,13 +6181,18 @@ function autoResize(){
     _composerAutoResizeRaf=0;
   }
   const el=$('msg');
+  const _prevComposerH=el.offsetHeight;
   el.style.height='auto';
   el.style.height=Math.min(el.scrollHeight,200)+'px';
   updateSendBtn();
   // #5514/#5515: growing the composer shrinks the flex:1 transcript viewport, so
   // a reader pinned to the bottom would be stranded above it ("scrolls up 1 row
-  // per composer row"). Re-pin the transcript when it's genuinely still pinned.
-  if(typeof _repinMessagesAfterComposerResize==='function') _repinMessagesAfterComposerResize();
+  // per composer row"). Re-pin the transcript when it's genuinely still pinned —
+  // but only when the composer actually GREW (a shrink enlarges the viewport and
+  // can't strand a reader), so the common no-height-change keystroke skips the
+  // re-pin's DOM read entirely. The #composerWrap ResizeObserver is the safety
+  // net for any growth path that doesn't route through here.
+  if(el.offsetHeight>_prevComposerH && typeof _repinMessagesAfterComposerResize==='function') _repinMessagesAfterComposerResize();
 }
 function scheduleComposerAutoResize(){
   if(typeof requestAnimationFrame!=='function'){autoResize();return;}

tests/test_issue5514_composer_grow_scroll_pin.py

@@ -65,8 +65,10 @@ def test_autoresize_calls_the_repin():
     body = MESSAGES_JS[start:end]
     # The height write must still be there...
     assert "el.style.height=Math.min(el.scrollHeight,200)+'px'" in body
-    # ...and the re-pin must be called after it.
+    # ...and the re-pin must be called after it, guarded so it only fires when the
+    # composer actually grew (skips the DOM read on a no-height-change keystroke).
     assert "_repinMessagesAfterComposerResize()" in body
+    assert "el.offsetHeight>_prevComposerH" in body
 
 
 def test_resize_observer_installed_on_composer():