feat(windows-drivers): STEP 7 — HDR/FP16 (validated on-glass: Mac connects WITH HDR)

The pf-vdisplay driver now advertises HDR/FP16 and the full glass-to-glass HDR path works
end-to-end — validated LIVE: the Mac client connected to the .173 host WITH HDR (display_hdr=true,
FP16 ring -> NVENC P010). The STEP-3 assumption that FP16 needs a higher UmdfExtensions was WRONG:
IddCx0102 + CAN_PROCESS_FP16 + the *2 DDIs works (the oracle proved it; confirmed on-glass
IddCxAdapterInitAsync -> 0x0 WITH the FP16 cap set). Driver-only change — the host FP16-ring ->
NVENC-P010 path and the HDR EDID were already in place.

- adapter.rs: caps.Flags = IDDCX_ADAPTER_FLAGS_CAN_PROCESS_FP16.
- entry.rs: register the 6 *2/HDR callbacks (ParseMonitorDescription2, MonitorQueryTargetModes2,
  AdapterCommitModes2, AdapterQueryTargetInfo, MonitorSetDefaultHdrMetaData, MonitorSetGammaRamp)
  ALONGSIDE the v1 set (matching the oracle — CAN_PROCESS_FP16 OBLIGATES the *2 DDIs or the
  framework rejects the adapter at init; STEP 3 rejected FP16 only because they weren't registered).
- callbacks.rs: parse_monitor_description2 + monitor_query_modes2 now fill IDDCX_MONITOR_MODE2 /
  IDDCX_TARGET_MODE2 with BitsPerComponent (8|10 bpc RGB); query_target_info already reports
  IDDCX_TARGET_CAPS_HIGH_COLOR_SPACE; set_default_hdr_metadata + set_gamma_ramp accept (the gamma
  one is mandatory under FP16).
- monitor.rs: wire_bits() (Rgb 8|10, no YCbCr) + target_mode2().
- EDID + INF UNCHANGED (the EDID already carries the CTA-861.3 BT.2020 + ST.2084/PQ block; the INF
  stays UmdfExtensions=IddCx0102).

Built via the ultracode flow (STEP-7 map workflow -> agent-implement -> box build [driver green] ->
deploy -> on-glass HDR). OPERATIONAL NOTE: do NOT Disable/Enable the IddCx devnode to reload it —
that leaves the adapter STOPPED in the persisted WUDFHost process (ADAPTER OnceLock survives), so
monitor-create then fails with 0xc00002b6 (INDIRECT_DISPLAY_DEVICE_STOPPED). Kill the pf_vdisplay
WUDFHost process (or reboot) for a clean adapter re-init.

This completes the pf-vdisplay rewrite STEP 0-7, all on-glass validated (loads, adapter inits,
monitor appears, swap-chain drain, IDD-push frames at ~235fps, and HDR). Remaining: STEP 8 (unsafe-
reduction + delete the old vdisplay-driver tree + the vendored SudoVDA driver + unbundle from the
installer = the SudoVDA drop).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packaging/windows/drivers/pf-vdisplay/src/entry.rs

@@ -76,10 +76,18 @@ extern "C" fn driver_add(_driver: WDFDRIVER, mut init: PWDFDEVICE_INIT) -> NTSTA
     cfg.EvtIddCxMonitorGetDefaultDescriptionModes = Some(callbacks::monitor_get_default_modes);
     cfg.EvtIddCxMonitorQueryTargetModes = Some(callbacks::monitor_query_modes);
     cfg.EvtIddCxAdapterCommitModes = Some(callbacks::adapter_commit_modes);
-    // SDR config — matches the working upstream virtual-display-rs. The *2 / gamma / HDR-metadata /
-    // query-target-info callbacks are FP16-OBLIGATED: registering them while caps declare no FP16 makes the
-    // framework's adapter Validate reject (ddivalidation.cpp:797 -> INVALID_PARAMETER). They return with
-    // FP16 caps under a higher UmdfExtensions binding in STEP 7 (HDR).
+    // STEP 7 (HDR): the *2 mode DDIs + the gamma/HDR-metadata/query-target-info callbacks. The adapter
+    // caps now set CAN_PROCESS_FP16 (adapter.rs), which OBLIGATES this whole set — without them the OS
+    // rejects the adapter at init ("Failed to get adapter"). The proven oracle (entry.rs) registers the *2
+    // variants ALONGSIDE the v1 callbacks above (NOT instead of them) — the OS prefers the *2 on IddCx
+    // 1.10 and falls back to v1 down-level — so we replicate exactly: keep both. The framework no longer
+    // rejects the *2 set because the FP16 cap is now present (the only reason STEP 3 had to drop them).
+    cfg.EvtIddCxParseMonitorDescription2 = Some(callbacks::parse_monitor_description2);
+    cfg.EvtIddCxMonitorQueryTargetModes2 = Some(callbacks::monitor_query_modes2);
+    cfg.EvtIddCxAdapterCommitModes2 = Some(callbacks::adapter_commit_modes2);
+    cfg.EvtIddCxAdapterQueryTargetInfo = Some(callbacks::query_target_info);
+    cfg.EvtIddCxMonitorSetDefaultHdrMetaData = Some(callbacks::set_default_hdr_metadata);
+    cfg.EvtIddCxMonitorSetGammaRamp = Some(callbacks::set_gamma_ramp);
     cfg.EvtIddCxMonitorAssignSwapChain = Some(callbacks::assign_swap_chain);
     cfg.EvtIddCxMonitorUnassignSwapChain = Some(callbacks::unassign_swap_chain);
     cfg.EvtIddCxDeviceIoControl = Some(callbacks::device_io_control);