feat: GPUI desktop port foundation

- scene crate: full project/scene/element model, serde round-trip
  proven against the web SerializedProject shape
- transfer crate: .ocp zip container, cross-compat with web fflate
  archives proven in both directions
- storage crate: filesystem project store replacing IndexedDB,
  .ocp import/export
- media crate: ffmpeg-next 8 decoder (frames, audio, thumbnails,
  waveform summaries)
- playback crate: wall-clock anchored, frame-rounded playback clock
- gpu crate: native texture readback; compositor renders headless
  offscreen on Vulkan (spike test)
- flake devshell: rust toolchain, GPUI native deps, ffmpeg dev,
  bindgen clang args; GPUI hello-world builds
- port plan in notes/gpui-port.md

1 files changed, 49 insertions, 0 deletions

diff --git a/script/cross-check.ts b/script/cross-check.ts
new file mode 100644
index 00000000..4ea430ba
--- /dev/null
+++ b/script/cross-check.ts
@@ -0,0 +1,49 @@
+import { readFileSync, writeFileSync } from "node:fs";
+import {
+	buildProjectArchive,
+	parseProjectArchive,
+} from "../apps/web/src/project/transfer/container";
+
+const direction = process.argv[2];
+
+if (direction === "build") {
+	const projectJson = JSON.stringify({
+		version: 7,
+		metadata: { id: "web-built" },
+		nested: { value: 42 },
+	});
+	const archive = buildProjectArchive({
+		projectJson,
+		media: [
+			{
+				metadata: {
+					id: "web-asset",
+					name: "web clip.mov",
+					mediaType: "video",
+					fileType: "video/quicktime",
+					lastModified: 1_753_000_000_000,
+					width: 1280,
+					height: 720,
+					duration: 3.25,
+				},
+				data: new Uint8Array([9, 8, 7, 6]),
+			},
+		],
+	});
+	writeFileSync("/tmp/web-built.ocp", archive);
+	console.log("web-built.ocp written");
+} else if (direction === "parse") {
+	const archive = readFileSync("/tmp/rust-built.ocp");
+	const parsed = parseProjectArchive({ archive });
+	console.log(
+		JSON.stringify({
+			project: parsed.project,
+			media: parsed.media,
+			firstBytes: Array.from(
+				parsed.readMediaData({ entry: parsed.media[0]?.entry ?? "" }),
+			),
+		}),
+	);
+} else {
+	throw new Error("usage: bun cross-check.ts build|parse");
+}