feat(cli): bake proxies into published archives (#2595)

* feat(studio-server): serve H.264 proxies from the preview route

Wires the codec manifest and the transcoder into the preview surface: the route
negotiates a proxy via a query param and serves it through the existing range
and ETag machinery, composition HTML carries a codec map for the runtime, and
hostile assets pre-warm so a first play does not wait on a cold transcode.
Exposes the three subpath exports the CLI surfaces consume upstack.

Drops the TEMP fallow entry added with the transcoder: it has real importers now.

* fix(studio-server): publish media proxy exports

* fix(parsers): scan HTML comments linearly

* feat(cli): let projects opt out of automatic proxying

Adds media.autoProxy to hyperframes.json plus --proxy/--no-proxy flags, and
forwards the resolved value into the studio and preview servers and the vite
adapter. Lands before the runtime slice that turns auto-proxying on, so the
switch exists before there is any behavior to switch off.

* fix(cli): align media config schema

* feat(core): swap undecodable video to its proxy at runtime

Adds the browser-side half: before first load the runtime consults the injected
codec map and swaps a hostile source to its proxy, and if a video still reports
zero decodable width it rescues it reactively. An HEVC file carrying AAC fires
no error event, so zero videoWidth, not the error event, is the reliable signal.
Audio elements and alpha sources are never proxied, render mode never proxies,
and each swap evicts the element's stale sync state and reports once.

This completes the loop: auto-proxying is live for preview and studio from here.
The opt-out (media.autoProxy, --no-proxy) shipped in the previous slice.

* feat(cli): serve proxies from play, present, and the static project server

Adds proxy negotiation to the CLI-side servers and gives play byte-range
serving it never had, so a swapped video can seek. The static project server
behind check, snapshot, compare and friends injects the codec map once, so all
of its callers inherit the behavior; snapshot forwards its own proxy flag.

* fix(cli): serve proxies for camera formats

* feat(cli): resolve proxies before check's timed browser phase

check pre-resolves hostile assets so a cold transcode cannot exhaust the
render-ready budget, and surfaces the runtime's proxy diagnostics as findings
so a swap is visible rather than silent.

* feat(cli): bake proxies into published archives

Published pages are static, so there is no server to negotiate with: publish
transcodes proxies for hostile assets into the archive and rewrites the video
sources that point at them. Audio elements keep their originals, since audio
decodes independently of the video codec.

Splits the archive build from the zip step so publish can transform between
them. cloud render keeps calling the unchanged composition and still uploads
originals, which its regression test pins.

* fix(cli): harden proxy pre-resolution

* fix(cli): surface publish proxy outcomes

* test(cli): remove ffmpeg from archive guard

* test(cli): normalize publish fixture path

packages/cli/src/utils/publishProject.test.ts

@@ -21,11 +21,13 @@ vi.mock("./projectLink.js", () => ({
 }));
 
 import {
+  buildPublishFileMap,
   createPublishArchive,
   getPublishApiBaseUrl,
   localizeExternalAssets,
   publishProjectArchive,
   uploadTimeoutMs,
+  zipPublishFileMap,
 } from "./publishProject.js";
 
 function makeProjectDir(): string {
@@ -208,6 +210,41 @@ describe("createPublishArchive", () => {
   });
 });
 
+describe("createPublishArchive (U6 cloud-render regression guard)", () => {
+  // `cloud/render.ts` (`maybeUploadProject`) calls `createPublishArchive`
+  // directly and must never see baked proxies (R2): this pins that
+  // `createPublishArchive` is exactly the thin composition of
+  // `buildPublishFileMap` + `zipPublishFileMap` with no baking hook, and that
+  // a local video asset's original bytes/HTML pass through unmodified.
+  it("keeps a source video byte-identical and excludes proxies from the cloud-render archive", () => {
+    const dir = makeProjectDir();
+    try {
+      writeFileSync(
+        join(dir, "index.html"),
+        `<html><body><video src="clip.mp4"></video></body></html>`,
+        "utf-8",
+      );
+      const originalVideo = Buffer.from("original-video-bytes");
+      writeFileSync(join(dir, "clip.mp4"), originalVideo);
+
+      const direct = createPublishArchive(dir);
+      const composed = zipPublishFileMap(buildPublishFileMap(dir));
+
+      expect(direct.buffer.equals(composed.buffer)).toBe(true);
+      expect(direct.fileCount).toBe(composed.fileCount);
+
+      const zip = new AdmZip(direct.buffer);
+      const entries = zip.getEntries().map((e) => e.entryName);
+      expect(entries).toEqual(expect.arrayContaining(["index.html", "clip.mp4"]));
+      expect(entries.some((e) => e.startsWith("_proxy/"))).toBe(false);
+      expect(zip.readFile("clip.mp4")?.equals(originalVideo)).toBe(true);
+      expect(zip.readAsText("index.html")).toContain('src="clip.mp4"');
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});
+
 describe("localizeExternalAssets", () => {
   it("copies external src/href assets and rewrites HTML paths", () => {
     const result = localizeSingleAsset("logo.png", "PNG_DATA", (rel) =>