fix(windows/cursor): record the declare from the ADD request — the only place every one passes

CURSOR_DECLARED was set in capture_virtual_output, which is not on the Windows
prep path, so it was never true and the between-session clean returned at its
first gate every time, silently. Both on-glass runs that appeared to 'not fire'
were this; the one run that did fire was a build with no gate at all.

Move it to the ADD request in the driver module, which every session that wants
a hardware cursor goes through by construction.

crates/pf-vdisplay/src/vdisplay/windows/pf_vdisplay.rs

@@ -248,18 +248,12 @@ fn recycle_wudfhost() -> bool {
 }
 
 /// Has this host process DECLARED an IddCx hardware cursor since the adapter was last restarted?
-/// Set by [`note_cursor_declared`] when a session delivers a cursor channel; cleared when
-/// [`clean_cursor_for_next_session`] restarts the device. This is the host's own mirror of the
+/// Set by the ADD path when a session ASKS for a hardware cursor (the one place every declare
+/// passes through); cleared when the declare is dropped. The host's own mirror of the
 /// driver's `DECLARED_TARGETS` — cheaper than probing, and it only ever needs to be right about
 /// "did WE dirty it", because a declare from an earlier BOOT is handled by the start-up clean.
 static CURSOR_DECLARED: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(false);
 
-/// Record that a session declared the hardware cursor (it delivered a cursor channel), so the next
-/// session that does NOT want one knows the adapter needs cleaning.
-pub fn note_cursor_declared() {
-    CURSOR_DECLARED.store(true, std::sync::atomic::Ordering::Relaxed);
-}
-
 /// Give the NEXT session back the lossless cursor: if an earlier session on this host declared the
 /// hardware cursor and this one does not want it, restart the device to clear the sticky declare.
 ///
@@ -928,7 +922,16 @@ impl VdisplayDriver for PfVdisplayDriver {
             // (DWM stops compositing the pointer into the frame); the capture layer delivers the
             // CursorShm section right after its ring. Zero toward older drivers is harmless —
             // the host only sets this when the handshake-reported proto is >= 5.
-            hw_cursor: hw_cursor as u32,
+            hw_cursor: {
+                // The ONE place guaranteed to see every declare: the ADD request that asks for it.
+                // (An earlier attempt recorded this from `capture_virtual_output`, which is not on
+                // the Windows prep path — the flag stayed false and the between-session clean
+                // silently never ran.)
+                if hw_cursor {
+                    CURSOR_DECLARED.store(true, std::sync::atomic::Ordering::Relaxed);
+                }
+                hw_cursor as u32
+            },
         };
         // SET_RENDER_ADAPTER (opt-in; pf-vdisplay IMPLEMENTS it). Non-fatal on failure: the driver reports
         // its real render LUID in the shared header, so the host binds correctly even if this is ignored.

crates/punktfunk-host/src/capture.rs

@@ -231,12 +231,6 @@ pub fn capture_virtual_output(
     // Cursor-forward sessions (M2c): hand the capturer the v5 cursor-channel delivery closure —
     // its presence opts the session in (the capturer creates + delivers the CursorShm section,
     // the driver declares the IddCx hardware cursor). Built exactly like `sender` above.
-    // Remember that this host declared, so the NEXT session that wants no hardware cursor knows to
-    // clear it (`clean_cursor_for_next_session`) instead of self-compositing for its whole life.
-    #[cfg(target_os = "windows")]
-    if want.hw_cursor {
-        crate::vdisplay::driver::note_cursor_declared();
-    }
     let cursor_sender: Option<pf_capture::CursorChannelSender> = want.hw_cursor.then(|| {
         std::sync::Arc::new(
             move |req: &pf_driver_proto::control::SetCursorChannelRequest| {