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/util/bit_vector.cpp

@@ -0,0 +1,92 @@
+// 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/util/bit_vector.h"
+
+#include <cassert>
+#include <iostream>
+
+namespace spvtools {
+namespace utils {
+
+void BitVector::ReportDensity(std::ostream& out) {
+  uint32_t count = 0;
+
+  for (BitContainer e : bits_) {
+    while (e != 0) {
+      if ((e & 1) != 0) {
+        ++count;
+      }
+      e = e >> 1;
+    }
+  }
+
+  out << "count=" << count
+      << ", total size (bytes)=" << bits_.size() * sizeof(BitContainer)
+      << ", bytes per element="
+      << (double)(bits_.size() * sizeof(BitContainer)) / (double)(count);
+}
+
+bool BitVector::Or(const BitVector& other) {
+  auto this_it = this->bits_.begin();
+  auto other_it = other.bits_.begin();
+  bool modified = false;
+
+  while (this_it != this->bits_.end() && other_it != other.bits_.end()) {
+    auto temp = *this_it | *other_it;
+    if (temp != *this_it) {
+      modified = true;
+      *this_it = temp;
+    }
+    ++this_it;
+    ++other_it;
+  }
+
+  if (other_it != other.bits_.end()) {
+    modified = true;
+    this->bits_.insert(this->bits_.end(), other_it, other.bits_.end());
+  }
+
+  return modified;
+}
+
+std::ostream& operator<<(std::ostream& out, const BitVector& bv) {
+  out << "{";
+  for (uint32_t i = 0; i < bv.bits_.size(); ++i) {
+    BitVector::BitContainer b = bv.bits_[i];
+    uint32_t j = 0;
+    while (b != 0) {
+      if (b & 1) {
+        out << ' ' << i * BitVector::kBitContainerSize + j;
+      }
+      ++j;
+      b = b >> 1;
+    }
+  }
+  out << "}";
+  return out;
+}
+
+bool BitVector::operator==(const BitVector& other) const {
+  size_t max_size = std::max(bits_.size(), other.bits_.size());
+  for (size_t i = 0; i < max_size; ++i) {
+    BitContainer b1 = (i < bits_.size()) ? bits_[i] : 0;
+    BitContainer b2 = (i < other.bits_.size()) ? other.bits_[i] : 0;
+    if (b1 != b2) return false;
+  }
+  return true;
+}
+
+}  // namespace utils
+}  // namespace spvtools