Four more tree-shape tools routed through the existing dispatcher
+ confirm modal + audit log. All take leaf_id args (single or pair)
that must be MCP-allowed via the per-pane chip; apply_preset takes
a typed PresetName enum (single, two_columns, three_columns,
two_rows, two_by_two) plus an allow_drops boolean.
apply_preset's data-loss case is handled non-interactively: if the
preset has fewer slots than the current pane count and allow_drops
is not set, the frontend handler throws with a descriptive message
listing the leaf labels that would be killed, so Claude can decide
whether to retry with allow_drops=true rather than the user being
ambushed by a destructive confirm modal.
promote_pane errors with "no perpendicular split above it" when the
parent shares orientation with the grandparent (same condition the
Ctrl+Shift+P shortcut uses to toast a no-op).
Extracted a require_visible_leaf helper on TileService since 4+ of
the v2 tools now do the same mirror-presence + cloned-metadata
check. Same args_repr convention as set_label so policy rules like
"close_pane" (bare tool name) work uniformly.
megaproxy
e0ce223985