fix(cli): pin arm64 render Chromium to Playwright headless-shell (#2039) (#2040)

The arm64 render image had no pinned browser: chrome-for-testing publishes
no linux-arm64 build, so Dockerfile.render fell back to Debian bookworm's
rolling `chromium` package. Its current arm64 build (150.0.7871.46) SIGTRAPs
at startup (exit 133), breaking `render --docker` 100% on Apple Silicon.

Install a pinned, non-Debian chrome-headless-shell from Playwright on arm64
(Google's build, not Debian's repackage). The wrapper wires whichever binary
landed into PRODUCER_HEADLESS_SHELL_PATH and now fails the build loudly if
neither is present, instead of silently using the broken Debian chromium.
Bonus: arm64 gains BeginFrame deterministic capture it previously lacked.
amd64 path is unchanged.

Verified on Apple Silicon: same arm64 image, Debian chromium 150 -> exit 133,
Playwright arm64 headless-shell (Chromium 149) -> exit 0.

packages/cli/src/utils/dockerRunArgs.ts

@@ -22,9 +22,9 @@ export interface DockerRunArgsInput {
    * resolves to the host architecture via `resolveDockerPlatform()`. Pinning
    * to `linux/amd64` on an arm64 host (the legacy default) forces qemu
    * emulation of chrome-headless-shell, which segfaults or stalls on Apple
-   * Silicon — see issue #1193. Native `linux/arm64` falls back to the
-   * system chromium baked into the image at the cost of byte-for-byte
-   * parity with amd64 renders.
+   * Silicon — see issue #1193. Native `linux/arm64` uses Playwright's pinned
+   * arm64 chrome-headless-shell baked into the image at the cost of
+   * byte-for-byte parity with amd64 renders.
    */
   platform?: string;
   options: DockerRenderOptions;