fix(workspace): hidden bullet actions on phones, no second extract, notice layout

- The floating bullet actions only react to hover on devices with a real
  pointer; a tap on a phone made the invisible buttons clickable.
- A bullet that is only a note link (plus hashtags) can no longer be
  extracted: button and /extract are hidden, the server answers 400.
- Extract notice on phones sits above the bottom navigation, text on
  top (two lines max) with the actions below.
- Release v0.26.1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/storage/restructure.go

@@ -20,6 +20,7 @@ var (
 	ErrBlockNotFound = errors.New("Punkt nicht gefunden")
 	ErrBranchLocked  = errors.New("Jemand anderes bearbeitet gerade einen Punkt in diesem Ast. Bitte kurz warten.")
 	ErrMergeSelf     = errors.New("Eine Notiz kann nicht mit sich selbst zusammengeführt werden")
+	ErrAlreadyNote   = errors.New("Dieser Punkt verweist schon auf eine eigene Notiz")
 	ErrMergeNotOwner = errors.New("Zusammenführen geht nur mit eigenen Notizen als Quelle")
 )
 
@@ -37,6 +38,8 @@ func (s *Store) readCollabDoc(docID string) (*collab.Doc, error) {
 var (
 	titlePrefixRe = regexp.MustCompile(`^(\s*(-|\*|#{1,6}|\[[ xX]?\])\s+)+`)
 	titleTagRe    = regexp.MustCompile(`(^|\s)#[\p{L}0-9_-]+`)
+	// A bullet that is only a link to a note (with hashtags), as left behind by ExtractBranch
+	noteLinkOnlyRe = regexp.MustCompile(`^\s*\[\[[^\]]+\]\](\s+#[\p{L}0-9_-]+)*\s*$`)
 )
 
 // branchTitle makes a note title from a bullet's text (without hashtags) and returns the hashtags,
@@ -116,6 +119,9 @@ func (s *Store) ExtractBranch(userID, docID, blockID string, a collab.Actor, lea
 		return nil, "", ErrBlockNotFound
 	}
 	root := flat[start]
+	if noteLinkOnlyRe.MatchString(root.Content) {
+		return nil, "", ErrAlreadyNote
+	}
 	var children []domain.DocumentBlock
 	ids := []string{root.ID}
 	for i := start + 1; i < len(flat) && flat[i].Level > root.Level; i++ {