fix(host): dual identical GPUs stream again — self-heal the IDD-push ring onto the driver's real render adapter

A box with two identical GPUs (twin RTX 4090s in the field report) died out
of pipeline retries with driver_status=2 (DRV_STATUS_TEX_FAIL, detail
0x80070057): SET_RENDER_ADAPTER pinned the driver to one twin at monitor ADD,
but the ring open re-ran the GPU picker, whose max-VRAM tie is settled by
DXGI enumeration order — which follows the primary display that the vdisplay
flow itself moves mid-session. Ring on one twin, swap-chain on the other →
the driver can't open the shared textures, and every retry repeats the same
wrong pick.

- wait_for_attach: TEX_FAIL becomes a typed AttachTexFail carrying the render
  LUID the driver reports in the shared frame header (written before the
  texture opens, so valid on failure) — the error now names both adapters
  instead of guessing "mismatch?".
- open_inner: on AttachTexFail with a different, non-zero driver LUID, rebind
  the ring there and reopen ONCE. Both candidates are real GPU adapters, so
  NVENC keeps getting a device it accepts.
- gpu::enumerate (Windows): sort the inventory by LUID so the max-VRAM tie,
  the env-substring first match, and twin occurrence numbering are stable for
  the boot instead of tracking the primary display.
- manager: record the ADD-time render pin on Monitor and warn on reuse when
  the current pick has moved away from it (the pick only takes effect on the
  next monitor create; /display/release forces one).
- pf_vdisplay: drop the "ADD render adapter DIFFERS from pinned" warn — the
  ADD reply carries IDARG_OUT_MONITORARRIVAL.OsAdapterLuid (the IddCx DISPLAY
  adapter, verified on-glass), not the render GPU, so the check compared
  unrelated LUIDs and fired on every ADD.

Verified on the RTX 4090 box: single-GPU streaming is unchanged (IddPush +
NVENC AV1 session, no new warnings). The rebind path needs a twin-GPU box —
until validated there, /display/release remains the manual recovery.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/punktfunk-host/src/gpu.rs

@@ -91,7 +91,8 @@ impl GpuInfo {
 }
 
 /// Assign the stable `id` + `occurrence` fields after enumeration (occurrence = index among
-/// same-(vendor,device) twins, in enumeration order).
+/// same-(vendor,device) twins, in inventory order — Windows sorts the inventory by LUID first so
+/// twin numbering is stable for the boot, see [`enumerate`]).
 fn assign_ids(gpus: &mut [GpuInfo]) {
     for i in 0..gpus.len() {
         let occ = gpus[..i]
@@ -268,6 +269,13 @@ pub(crate) fn enumerate() -> Vec<GpuInfo> {
             });
         }
     }
+    // Deterministic inventory order. DXGI enumerates the adapter owning the primary display first,
+    // and the vdisplay flow itself MOVES the primary mid-session (exclusive mode turns the physical
+    // screens off) — which flipped every order-relative selection between IDENTICAL twin GPUs from
+    // one call to the next (the max-VRAM tie, the env-substring first match, occurrence numbering):
+    // monitor ADD pinned the driver to one twin, the ring open picked the other → TEX_FAIL. LUIDs
+    // are creation-ordered and stable for the boot, so sorting by them makes selection stable too.
+    out.sort_by_key(|g| ((g.handle.luid_high as i64) << 32) | g.handle.luid_low as i64);
     assign_ids(&mut out);
     out
 }