[utkarshdalal]

android: A55 — the cursor rides the daemon's cursor plane

Branch cursor-plane-on-android (41aea0e), base gamenative (A52 is the last patch there). No longer stacked on #23: A55 applies over 0001-0050 alone. New patch android/patches/gamescope/0051-A55-cursor-plane-on-gamenative-drm.patch; the 0001-0051 train applies cleanly over a fresh export. CI build 41199397730.

Change

• DRMBackend.cpp init_drm: requests the daemon's GNDRM_CLIENT_CAP_CURSOR_LAYER (0x474E434C, "GNCL"). Accepted -> drm_cursor_plane on, logged drm: cursor: daemon cursor layer on (GNCL accepted, max 256x256), drm_cursor_plane=1. Rejected (old daemon) -> unchanged behaviour, logged once.
• Direct path (game buffer on the primary plane, the DXVK case): a cursor move commits the same primary framebuffer plus the moved cursor plane, no composite.
• Composite path (FSR/NIS/SGSR, filters, looks, refused buffers): composites everything except the cursor; a paint caused only by cursor motion re-commits the last composite instead of compositing again (skipped for fade, blur, ReShade, composite debug). If the two-plane commit is refused that frame composites the cursor in as before and that image is not offered to the plane again.
• steamcompmgr.cpp: a cursor motion is a repaint request like hasRepaint (picked up on the next vblank, painted on every flip type) but recorded as a cursor repaint, a motion serial the paint records, so a motion during a paint stays pending. A paint whose only cause is the cursor is flagged cursor-only and takes the cursor-only path (same primary framebuffer or the last composite, cursor plane moved, no composite). There is no idle gate on gamenative, so no extra wake is needed. wlserver.cpp: wlserver_oncursorevent uses the cursor repaint when the cursor is on the plane, hasRepaint otherwise.

Results (Retroid Pocket 6, 120 Hz, Dave the Diver, cap 60, with gamenative-drm real-cursor-plane; measured on the earlier build stacked on #23)

	cursor hidden	cursor moving
before (stacked build, A53/A54 only)	46.9 fps (pre shim fix)	70.78 presents/s: a full composite + flip per cursor move
+ A55 + daemon cursor layer	60.00	54.85, scan-out and cursor both DEVICE, picture intact

The remaining ~5 fps drop with the cursor moving is per-motion wineserver work on the game's main thread (not display); separate follow-up.

Needs the daemon PR for the plane to appear; without it (EINVAL) nothing changes.