v0.2.0: splats, copy/paste, faster homes, seat facing, and a full bug sweep

Frame Studio
- Gaussian splats (PLY, SPZ v2-v4), PLY vertex colours, panorama skies
- Copy, cut, paste and duplicate for objects, splats and world items
- Walkable-area rebake moved off the UI thread; viewport one frame sooner;
  refresh-locked pacing (FS_PACE=timer for the old one)
- Fixed: bundle thumbnail use-after-free crash, auto-save deleting
  environments, saves into scratch copies, edits lost on non-ASCII paths,
  unopenable manifests with inf/nan, bundle save data loss, opening a home
  marking it changed, gizmo NaN, long paths, many malformed-file crashes
- Updater verifies sha256, journals the swap and never leaves the exe missing

Frame Home
- Seats turn you to face their way
- Draw batching (Hand Tutorials up to ~20% less GPU time), cut-out EQUAL pass,
  late head-pose read before submit
- Proper queue-family hand-over to the compositor layer; layer descriptor
  generations and seqlocked slots; structural SPIR-V check
- Fixed: hangs/crashes on damaged .fenv files and shaders, render-pass
  validation error, sync hazard in the foveation smoothing pass, unverified
  update downloads, half-done installs

Tests: tests_loco/env_share/spv_check wired into CMake (FRAME_TESTS) and CI.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VsaXGU27gsrXjDoFtyFJP9

third_party/spirv-tools/source/val/validate_execution_limitations.cpp

@@ -0,0 +1,69 @@
+// Copyright (c) 2018 Google LLC.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "source/val/validate.h"
+#include "source/val/validation_state.h"
+
+namespace spvtools {
+namespace val {
+
+spv_result_t ValidateExecutionLimitations(ValidationState_t& _,
+                                          const Instruction* inst) {
+  if (inst->opcode() != spv::Op::OpFunction) {
+    return SPV_SUCCESS;
+  }
+
+  const auto func = _.function(inst->id());
+  if (!func) {
+    return _.diag(SPV_ERROR_INTERNAL, inst)
+           << "Internal error: missing function id " << inst->id() << ".";
+  }
+
+  for (uint32_t entry_id : _.FunctionEntryPoints(inst->id())) {
+    const auto* models = _.GetExecutionModels(entry_id);
+    if (models) {
+      if (models->empty()) {
+        return _.diag(SPV_ERROR_INTERNAL, inst)
+               << "Internal error: empty execution models for function id "
+               << entry_id << ".";
+      }
+      for (const auto model : *models) {
+        std::string reason;
+        if (!func->IsCompatibleWithExecutionModel(model, &reason)) {
+          return _.diag(SPV_ERROR_INVALID_ID, inst)
+                 << "OpEntryPoint Entry Point <id> " << _.getIdName(entry_id)
+                 << "s callgraph contains function <id> "
+                 << _.getIdName(inst->id())
+                 << ", which cannot be used with the current execution "
+                    "model:\n"
+                 << reason;
+        }
+      }
+    }
+
+    std::string reason;
+    if (!func->CheckLimitations(_, _.function(entry_id), &reason)) {
+      return _.diag(SPV_ERROR_INVALID_ID, inst)
+             << "OpEntryPoint Entry Point <id> " << _.getIdName(entry_id)
+             << "s callgraph contains function <id> " << _.getIdName(inst->id())
+             << ", which cannot be used with the current execution "
+                "modes:\n"
+             << reason;
+    }
+  }
+  return SPV_SUCCESS;
+}
+
+}  // namespace val
+}  // namespace spvtools