feat(host): vendor PyroWave + minimal Granite subset as crates/pyrowave-sys

Phase 0 of design/pyrowave-codec-plan.md — the opt-in wired-LAN ultra-low-
latency codec. Vendored at upstream 509e4f88 (API 0.4.0, Granite 44362775,
volk + vulkan-headers pins in PUNKTFUNK-VENDOR.txt), pruned to the 6.6 MB
the standalone no-renderer build needs; scripts/vendor-pyrowave.sh
reproduces the tree (a pin bump is protocol-affecting, plan §4.2).

build.rs drives the wrapper CMakeLists (static archives incl. a static
C-API lib upstream only ships shared) + bindgen over pyrowave.h; Linux and
Windows only, empty stub elsewhere (Apple gets a native Metal port, §4.7).
Offline-safe by construction: no network, no system lib, vendored Vulkan
headers — same model as the opus dep (flatpak builder has no network).

Phase-0 validation on .21 (RTX 5070 Ti, driver 610.43.03):
- upstream pyrowave-c-test + interop test (incl. dmabuf/DRM-modifier
  Vulkan<->Vulkan) pass, from the pristine AND the pruned tree
- GPU kernel times at ~1.6 bpp noise: encode/decode 0.090/0.042 ms @800p,
  0.146/0.067 @1080p, 0.226/0.103 @1440p, 0.477/0.201 @4K — order of
  magnitude under NVENC's 1-2 ms retrieve, CBR lands within ~100 B of
  target
- cargo test -p pyrowave-sys green (static link + API-version pin check)

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

crates/pyrowave-sys/vendor/pyrowave/Granite/ecs/ecs.cpp

@@ -0,0 +1,138 @@
+/* Copyright (c) 2017-2026 Hans-Kristian Arntzen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "ecs.hpp"
+
+namespace Granite
+{
+Entity *EntityPool::create_entity()
+{
+	Util::Hasher hasher;
+	hasher.u64(++cookie);
+	auto *entity = entity_pool.allocate(this, hasher.get());
+	entity->pool_offset = entities.size();
+	entities.push_back(entity);
+	return entity;
+}
+
+void EntityPool::free_component(Entity &entity, ComponentType id, ComponentNode *component)
+{
+	auto *c = component_types.find(id);
+	assert(c);
+	c->free_component(component->get());
+	component_nodes.free(component);
+
+	auto *component_groups = component_to_groups.find(id);
+	if (component_groups)
+	{
+		for (auto &group : *component_groups)
+		{
+			auto *g = groups.find(group.get_hash());
+			if (g)
+				g->remove_entity(entity);
+		}
+	}
+}
+
+void EntityPool::delete_entity(Entity *entity)
+{
+	{
+		auto &components = entity->get_components();
+		auto &list = components.inner_list();
+		auto itr = list.begin();
+		while (itr != list.end())
+		{
+			auto *component = itr.get();
+			itr = list.erase(itr);
+			free_component(*entity, component->get_hash(), component);
+		}
+	}
+
+	auto offset = entity->pool_offset;
+	assert(offset < entities.size());
+
+	entities[offset] = entities.back();
+	entities[offset]->pool_offset = offset;
+	entities.pop_back();
+	entity_pool.free(entity);
+}
+
+EntityPool::~EntityPool()
+{
+	{
+		auto &list = component_types.inner_list();
+		auto itr = list.begin();
+		while (itr != list.end())
+		{
+			auto *to_free = itr.get();
+			itr = list.erase(itr);
+			delete to_free;
+		}
+	}
+
+	reset_groups();
+	free_groups();
+}
+
+void EntityDeleter::operator()(Entity *entity)
+{
+	entity->get_pool()->delete_entity(entity);
+}
+
+void EntityPool::free_groups()
+{
+	auto &list = groups.inner_list();
+	auto itr = list.begin();
+	while (itr != list.end())
+	{
+		auto *to_free = itr.get();
+		itr = list.erase(itr);
+		delete to_free;
+	}
+	groups.clear();
+}
+
+void EntityPool::reset_groups()
+{
+	for (auto &group : groups)
+		group.reset();
+}
+
+void EntityPool::reset_groups_for_component_type(ComponentType id)
+{
+	auto *component_groups = component_to_groups.find(id);
+	if (component_groups)
+	{
+		for (auto &group : *component_groups)
+		{
+			auto *g = groups.find(group.get_hash());
+			if (g)
+				g->reset();
+		}
+	}
+}
+
+void ComponentSet::insert(ComponentType type)
+{
+	set.emplace_yield(type);
+}
+}