feat: room for many apps: qemu 512M, pool sized from RAM (448M, 114688 frames), user VA 32M -> 1G, display 8 windows (buffers at 0x1000_0000, stack 14 pages), pm app budget 24 MiB, init 16 children (notif bits moved)

crates/servers/display-server/src/host.rs

@@ -13,8 +13,9 @@ use crate::server::Host;
 use crate::windows::MAX_WINDOWS;
 
 /// Where slot `i`'s buffer is mapped in the display: 4 MiB apart, room for
-/// a 1280x800 window.
-const BUFFERS_VA: usize = 0x0080_0000;
+/// a 1280x800 window; high, clear of the GPU's mappings and of the heap,
+/// which grows from the bottom.
+const BUFFERS_VA: usize = 0x1000_0000;
 const BUFFER_SPAN: usize = 0x0040_0000;
 const PAGE: usize = 4096;