Fix sourceViewTag resolution timing for sheet transitions

findNodeHandle(ref.current) at render time returns undefined on the
first render since the ref isn't populated yet. Fix this by:

- Menu.Outer: use useEffect to resolve the tag after mount when the
  trigger ref is already populated
- LabelsBtn/ThreadgateBtn: use callback refs to capture the node
  handle in state immediately when the button mounts

https://claude.ai/code/session_011cNDhEb2cDgg5QbVuzEyH1

src/components/Menu/index.tsx

@@ -1,4 +1,12 @@
-import {cloneElement, Fragment, isValidElement, useMemo, useRef} from 'react'
+import {
+  cloneElement,
+  Fragment,
+  isValidElement,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from 'react'
 import {
   findNodeHandle,
   Pressable,
@@ -106,9 +114,14 @@ export function Outer({
 }>) {
   const context = useMenuContext()
   const {_} = useLingui()
-  const sourceViewTag = enableTransition
-    ? (findNodeHandle(context.triggerRef.current) ?? undefined)
-    : undefined
+  const [sourceViewTag, setSourceViewTag] = useState<number>()
+
+  useEffect(() => {
+    if (enableTransition && context.triggerRef.current) {
+      const tag = findNodeHandle(context.triggerRef.current)
+      if (tag != null) setSourceViewTag(tag)
+    }
+  }, [enableTransition, context.triggerRef])
 
   return (
     <Dialog.Outer

src/view/com/composer/labels/LabelsBtn.tsx

@@ -1,4 +1,4 @@
-import {useRef} from 'react'
+import {useState} from 'react'
 import {findNodeHandle, Keyboard, View} from 'react-native'
 import {msg} from '@lingui/core/macro'
 import {useLingui} from '@lingui/react'
@@ -30,7 +30,14 @@ export function LabelsBtn({
 }) {
   const control = Dialog.useDialogControl()
   const {_} = useLingui()
-  const btnRef = useRef<View>(null)
+  const [sourceViewTag, setSourceViewTag] = useState<number>()
+
+  const btnRef = (node: View | null) => {
+    if (node) {
+      const tag = findNodeHandle(node)
+      if (tag != null) setSourceViewTag(tag)
+    }
+  }
 
   const hasLabel = labels.length > 0
 
@@ -80,7 +87,7 @@ export function LabelsBtn({
         control={control}
         nativeOptions={{
           preventExpansion: true,
-          sourceViewTag: findNodeHandle(btnRef.current) ?? undefined,
+          sourceViewTag,
         }}>
         <Dialog.Handle />
         <DialogInner

src/view/com/composer/threadgate/ThreadgateBtn.tsx

@@ -1,4 +1,4 @@
-import {useEffect, useMemo, useRef, useState} from 'react'
+import {useEffect, useMemo, useState} from 'react'
 import {
   findNodeHandle,
   Keyboard,
@@ -52,7 +52,13 @@ export function ThreadgateBtn({
   const {_} = useLingui()
   const ax = useAnalytics()
   const control = Dialog.useDialogControl()
-  const btnRef = useRef<View>(null)
+  const [sourceViewTag, setSourceViewTag] = useState<number>()
+  const btnRef = (node: View | null) => {
+    if (node) {
+      const tag = findNodeHandle(node)
+      if (tag != null) setSourceViewTag(tag)
+    }
+  }
   const [threadgateNudged, setThreadgateNudged] = useThreadgateNudged()
   const [showTooltip, setShowTooltip] = useState(false)
   const [tooltipWasShown] = useState(!threadgateNudged)
@@ -175,7 +181,7 @@ export function ThreadgateBtn({
 
       <PostInteractionSettingsControlledDialog
         control={control}
-        sourceViewTag={findNodeHandle(btnRef.current) ?? undefined}
+        sourceViewTag={sourceViewTag}
         onSave={() => {
           if (persist) {
             persistChanges({