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/application/application.hpp

@@ -0,0 +1,106 @@
+/* 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.
+ */
+
+#pragma once
+#include "wsi.hpp"
+#include "application_wsi_events.hpp"
+#include "input.hpp"
+#include "application_glue.hpp"
+
+namespace Granite
+{
+class Application
+{
+public:
+	virtual ~Application();
+	virtual void render_frame(double frame_time, double elapsed_time) = 0;
+	bool init_platform(std::unique_ptr<Vulkan::WSIPlatform> platform);
+	bool init_wsi(Vulkan::ContextHandle context = {});
+	void teardown_wsi();
+
+	// Called after the frame is submitted for presentation.
+	// Can do "garbage collection" or similar batched cleanup
+	// that does not depend on submitting more graphics work.
+	virtual void post_frame();
+
+	// In early loading, we have not loaded SPIR-V yet.
+	// Rendering a background color or extremely basic shaders could work here.
+	// If compiling without SPIRV-Cross or compiler support in a shipping configuration,
+	// any SPIR-V must be provided inline through slangmosh or similar.
+	virtual void render_early_loading(double frame_time, double elapsed_time);
+	// In loading, we have access to SPIR-V, but compiling pipelines is not done yet.
+	// This stage is more suited for rendering splash screens or similar.
+	virtual void render_loading(double frame_time, double elapsed_time);
+
+	Vulkan::WSI &get_wsi()
+	{
+		return application_wsi;
+	}
+
+	Vulkan::WSIPlatform &get_platform()
+	{
+		return *platform;
+	}
+
+	virtual std::string get_name()
+	{
+		return "granite";
+	}
+
+	virtual unsigned get_version()
+	{
+		return 0;
+	}
+
+	virtual unsigned get_default_width()
+	{
+		return 1280;
+	}
+
+	virtual unsigned get_default_height()
+	{
+		return 720;
+	}
+
+	bool poll();
+	void run_frame();
+	void show_message_box(const std::string &str, Vulkan::WSIPlatform::MessageType type);
+
+protected:
+	void request_shutdown()
+	{
+		requested_shutdown = true;
+	}
+
+	void poll_input_tracker_async(InputTrackerHandler *override_handler);
+
+private:
+	std::unique_ptr<Vulkan::WSIPlatform> platform;
+	Vulkan::WSI application_wsi;
+	bool requested_shutdown = false;
+
+	// Ready state for deferred device initialization.
+	bool ready_modules = false;
+	bool ready_pipelines = false;
+	void check_initialization_progress();
+};
+}