fix some auto complete issues

src/lib/strings/mention-manip.ts

@@ -7,7 +7,7 @@ export function getMentionAt(
   text: string,
   cursorPos: number,
 ): FoundMention | undefined {
-  let re = /(^|\s)@([a-z0-9.]*)/gi
+  let re = /(^|\s)@([a-z0-9.-]*)/gi
   let match
   while ((match = re.exec(text))) {
     const spaceOffset = match[1].length

src/view/com/composer/text-input/TextInput.tsx

@@ -96,10 +96,11 @@ export const TextInput = forwardRef(function TextInputImpl(
       newRt.detectFacetsWithoutResolution()
       setRichText(newRt)
 
-      const prefix = getMentionAt(
-        newText,
-        textInputSelection.current?.start || 0,
-      )
+      // NOTE: BinaryFiddler
+      // onChangeText happens before onSelectionChange, cursorPos is out of bound if the user deletes characters,
+      const cursorPos = textInputSelection.current?.start ?? 0
+      const prefix = getMentionAt(newText, Math.min(cursorPos, newText.length))
+
       if (prefix) {
         setAutocompletePrefix(prefix.value)
       } else if (autocompletePrefix) {