docs: the Fullscreen kind describes the fixed compositor

cce-compositor@1d90ac2 honours a client's fullscreen request, including one
set before the first commit, so the plate and the README stop describing
that as a gap.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

 README.md   |  9 ++++-----
 src/main.rs | 13 ++++++-------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 5c81d87..89fd188 100644
--- a/README.md
+++ b/README.md
@@ -47,11 +47,10 @@ the selected kind. Tiled is not on the list because a client cannot ask for
 it: the compositor's toggle action tiles a floating window. A `mode_rule` in
 `config.kdl` can force a mode, or circular rendering, for an app_id.
 
-Two kinds show a gap in the current compositor rather than a feature: a
-Fullscreen child maps Floating, because cce acts only on the
-`request_fullscreen` signal and not on a fullscreen state set before the
-first commit, and a Background-layer child is never visible, because cce
-draws its desktop grid natively above that layer.
+One kind shows a gap in the current compositor rather than a feature: a
+Background-layer child is never visible, because cce draws its desktop grid
+natively above that layer. (A Fullscreen child used to map Floating too, until
+cce-compositor learned to honour client fullscreen requests in-process.)
 
 **XDG** — two buttons, `Open File` and `Save File`, that call the toolkit's
 `file_dialog` module (the XDG Desktop Portal file chooser, via `rfd`) on a
diff --git a/src/main.rs b/src/main.rs
index 012ceca..b8393d8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -197,13 +197,12 @@ as maximized. A mode_rule in\n\
 config.kdl can force a mode.",
             ChildKind::Fullscreen => "An xdg_toplevel that sets\n\
 fullscreen before its first\n\
-commit. cce acts only on the\n\
-later request_fullscreen\n\
-signal, so today it maps\n\
-Floating; the fullscreen\n\
-action still toggles it, and\n\
-Fullscreen mode then covers\n\
-the output.",
+commit. cce maps it straight\n\
+into Fullscreen mode, covering\n\
+the output with no border;\n\
+the fullscreen action toggles\n\
+it back to the size it mapped\n\
+at, and in again.",
             ChildKind::Utility => "A toplevel declaring\n\
 set_utility on the cce\n\
 window-management protocol:\n\