tiling: Don't store trees for outputs, but for indices

Cargo.lock

@@ -74,6 +74,12 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c5d78ce20460b82d3fa150275ed9d55e21064fc7951177baacf86a145c4a4b1f"
 
+[[package]]
+name = "atomic_float"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62af46d040ba9df09edc6528dae9d8e49f5f3e82f55b7d2ec31a733c38dbc49d"
+
 [[package]]
 name = "atomic_refcell"
 version = "0.1.8"
@@ -292,6 +298,7 @@ name = "cosmic-comp"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "atomic_float",
  "bitflags",
  "edid-rs",
  "egui",