fix(PromptComposer): clear empty editor fillers before chip insertion

Insert a helper that strips filler-only editor content (stray <br> and
caret-anchor text nodes) before inserting reference/annotation chips and
on paste, so chips no longer land after an empty line. Also anchor the
caret after each inserted/updated chip and reorder focus/insert so the
caret reliably follows the new chip.

.gitignore

@@ -8,9 +8,4 @@ frontend/.vercel/*
 frontend/.vercel_build_output/*
 output/*
 .DS_Store
-.tools/bin/*
-
-# Embedded external tool/skill repos (checked out locally, not vendored)
-.ai-context/ai-context/
-.ai-context/zero-skills/
-.tools/mcp-zero/
+.tools/bin/*

frontend/src/ui/components/PromptComposer/index.tsx

@@ -499,6 +499,18 @@ function ensureCaretAnchorAfter(node: Node) {
   return { node: anchor, offset: caretAnchor.length };
 }
 
+function removeEmptyEditorFillers(editor: HTMLElement) {
+  const childNodes = Array.from(editor.childNodes);
+  if (childNodes.length === 0) return false;
+  const onlyFillers = childNodes.every((node) => {
+    if (node instanceof HTMLBRElement) return true;
+    return node.nodeType === Node.TEXT_NODE && stripCaretAnchors(node.textContent ?? "").length === 0;
+  });
+  if (!onlyFillers) return false;
+  editor.replaceChildren();
+  return true;
+}
+
 function placeCaretAfter(node: Node) {
   const range = document.createRange();
   const caret = isPromptChip(node) ? ensureCaretAnchorAfter(node) : null;
@@ -642,6 +654,7 @@ export const PromptComposer = forwardRef<
 
     const focus = options.focus ?? true;
     const pending = options.pending ?? false;
+    removeEmptyEditorFillers(editor);
     if (options.replacePending) {
       pendingReferenceChips(editor).forEach((chip) => {
         if (chip.dataset.referenceId === reference.id) return;
@@ -655,6 +668,7 @@ export const PromptComposer = forwardRef<
       const nextPending = existingPending ? pending : false;
       referencesRef.current.set(reference.id, { ...reference, pending: nextPending });
       setReferenceChipPending(existingChip, nextPending);
+      ensureCaretAnchorAfter(existingChip);
       if (focus) {
         editor.focus();
         placeCaretAfter(existingChip);
@@ -674,10 +688,11 @@ export const PromptComposer = forwardRef<
       range.collapse(false);
     }
 
-    if (focus) editor.focus();
     range.deleteContents();
     range.insertNode(chip);
+    ensureCaretAnchorAfter(chip);
     if (focus) {
+      editor.focus();
       placeCaretAfter(chip);
       savedRangeRef.current = window.getSelection()?.rangeCount ? window.getSelection()?.getRangeAt(0).cloneRange() ?? null : null;
     }
@@ -741,6 +756,7 @@ export const PromptComposer = forwardRef<
       const editor = editorRef.current;
       if (!editor) return;
 
+      removeEmptyEditorFillers(editor);
       annotationsRef.current.set(annotation.id, annotation);
       const chip = createAnnotationChip(annotation);
       const storedRange = savedRangeRef.current;
@@ -750,9 +766,10 @@ export const PromptComposer = forwardRef<
         range.collapse(false);
       }
 
-      editor.focus();
       range.deleteContents();
       range.insertNode(chip);
+      ensureCaretAnchorAfter(chip);
+      editor.focus();
       placeCaretAfter(chip);
       savedRangeRef.current = window.getSelection()?.rangeCount ? window.getSelection()?.getRangeAt(0).cloneRange() ?? null : null;
       emitChangeFromDom(false);
@@ -842,6 +859,10 @@ export const PromptComposer = forwardRef<
     if (!editor || !selection || selection.rangeCount === 0) return;
     const range = selection.getRangeAt(0);
     if (!rangeBelongsToEditor(range, editor)) return;
+    if (removeEmptyEditorFillers(editor)) {
+      range.selectNodeContents(editor);
+      range.collapse(false);
+    }
 
     range.deleteContents();
     if (hasPromptImageReferences(pastedText)) {