fix(cli): keep browser GPU opt-in for local renders

docs/guides/rendering.mdx

@@ -65,7 +65,8 @@ Render your Hyperframes [compositions](/concepts/compositions) to MP4, MOV, or W
 
     **Pros:**
     - Fast startup, no container overhead
-    - Can use your system GPU for Chrome/WebGL capture by default
+    - Uses software Chrome/WebGL capture by default for stable frame output
+    - Can opt into your system GPU for Chrome/WebGL capture with `--browser-gpu`
     - Can use your system GPU for hardware-accelerated encoding (with `--gpu`)
     - Best for iterative development
 
@@ -124,7 +125,7 @@ Render your Hyperframes [compositions](/concepts/compositions) to MP4, MOV, or W
 | `--workers` | 1-8 or `auto` | auto | Parallel render workers (see [Workers](#workers) below) |
 | `--max-concurrent-renders` | 1-10 | 2 | Max simultaneous renders via the producer server (see [Concurrent Renders](#concurrent-renders) below) |
 | `--gpu` | — | off | GPU encoding (NVENC, VideoToolbox, VAAPI, QSV) |
-| `--browser-gpu` / `--no-browser-gpu` | — | on locally, off in Docker | Use or opt out of host GPU acceleration for local Chrome/WebGL capture |
+| `--browser-gpu` / `--no-browser-gpu` | — | software | Use or opt out of host GPU acceleration for local Chrome/WebGL capture. Set `PRODUCER_BROWSER_GPU_MODE=auto` to probe hardware availability |
 | `--hdr` | — | off | Force HDR output even if no HDR sources are detected (MP4 only). See [HDR Rendering](/guides/hdr) |
 | `--sdr` | — | off | Force SDR output even if HDR sources are detected |
 | `--docker` | — | off | Use Docker for [deterministic rendering](/concepts/determinism) |

docs/packages/cli.mdx

@@ -597,8 +597,8 @@ This is suppressed in CI environments, non-TTY shells, and when `HYPERFRAMES_NO_
     # With options
     npx hyperframes render --output output.mp4 --fps 60 --quality high
 
-    # Opt out of local browser GPU capture
-    npx hyperframes render --no-browser-gpu --output cpu-browser.mp4
+    # Opt in to local browser GPU capture
+    npx hyperframes render --browser-gpu --output gpu-browser.mp4
 
     # Add hardware FFmpeg encoding
     npx hyperframes render --gpu --output gpu.mp4
@@ -617,7 +617,7 @@ This is suppressed in CI environments, non-TTY shells, and when `HYPERFRAMES_NO_
     | `--sdr` | — | off | Force SDR output even if HDR sources are detected |
     | `--workers` | 1-8 | 4 | Parallel render workers |
     | `--gpu` | — | off | GPU encoding (NVENC, VideoToolbox, VAAPI, QSV) |
-    | `--browser-gpu` / `--no-browser-gpu` | — | on locally, off in Docker | Use or opt out of host GPU acceleration for local Chrome/WebGL capture |
+    | `--browser-gpu` / `--no-browser-gpu` | — | software | Use or opt out of host GPU acceleration for local Chrome/WebGL capture. Set `PRODUCER_BROWSER_GPU_MODE=auto` to probe hardware availability |
     | `--docker` | — | off | Use Docker for [deterministic rendering](/concepts/determinism) |
     | `--quiet` | — | off | Suppress verbose output |
     | `--variables` | JSON object | — | Variable overrides merged over `data-composition-variables` defaults. Read via `window.__hyperframes.getVariables()` |

docs/packages/producer.mdx

@@ -226,7 +226,7 @@ When GPU encoding is enabled, Hyperframes detects the available FFmpeg hardware
 npx hyperframes doctor
 ```
 
-The CLI enables local Chrome/WebGL GPU capture automatically and supports `--no-browser-gpu` as an opt-out. When using the producer API directly, pass an engine config override:
+The CLI uses software Chrome/WebGL capture by default for stable cross-platform frame output. Use `--browser-gpu` to opt into host GPU capture, or set `PRODUCER_BROWSER_GPU_MODE=auto` to probe hardware availability and fall back to software. When using the producer API directly, pass an engine config override:
 
 ```typescript
 import { resolveConfig } from '@hyperframes/producer';

packages/cli/src/commands/render.test.ts

@@ -84,7 +84,7 @@ describe("renderLocal browser GPU config", () => {
     });
   }, 15_000);
 
-  it("forwards browserGpuMode='auto' into producer config (probe-then-choose)", async () => {
+  it("forwards browserGpuMode='auto' into producer config when explicitly requested by a caller", async () => {
     await renderLocal("/tmp/project", "/tmp/out.mp4", {
       fps: { num: 30, den: 1 },
       quality: "standard",
@@ -102,7 +102,7 @@ describe("renderLocal browser GPU config", () => {
     });
   });
 
-  it("passes an explicit hardware override for default local browser GPU", async () => {
+  it("passes an explicit hardware override for --browser-gpu", async () => {
     await renderLocal("/tmp/project", "/tmp/out.mp4", {
       fps: { num: 30, den: 1 },
       quality: "standard",
@@ -121,8 +121,8 @@ describe("renderLocal browser GPU config", () => {
   });
 
   it("resolves browser GPU from CLI flags, Docker mode, and env fallback", () => {
-    // Default (no flag, no env): auto — engine probes and chooses.
-    expect(resolveBrowserGpuForCli(false, undefined, undefined)).toBe("auto");
+    // Default (no flag, no env): software for stable cross-platform captures.
+    expect(resolveBrowserGpuForCli(false, undefined, undefined)).toBe("software");
     // Env override
     expect(resolveBrowserGpuForCli(false, undefined, "hardware")).toBe("hardware");
     expect(resolveBrowserGpuForCli(false, undefined, "software")).toBe("software");

packages/cli/src/commands/render.ts

@@ -18,7 +18,7 @@ export const examples: Example[] = [
   ["High quality at 60fps", "hyperframes render --fps 60 --quality high --output hd.mp4"],
   ["Deterministic render via Docker", "hyperframes render --docker --output deterministic.mp4"],
   ["Parallel rendering with 6 workers", "hyperframes render --workers 6 --output fast.mp4"],
-  ["Opt out of browser GPU render", "hyperframes render --no-browser-gpu --output cpu.mp4"],
+  ["Opt in to browser GPU render", "hyperframes render --browser-gpu --output gpu-browser.mp4"],
   ["HDR output (auto-detected)", "hyperframes render --output hdr-output.mp4"],
   [
     "Override composition variables (parametrized render)",
@@ -180,7 +180,7 @@ export default defineCommand({
     "browser-gpu": {
       type: "boolean",
       description:
-        "Force host GPU acceleration for Chrome/WebGL capture. Default: auto (probe on first launch; fall back to software if no GPU). Use --no-browser-gpu to force software (SwiftShader).",
+        "Force host GPU acceleration for Chrome/WebGL capture. Default: software (SwiftShader) for stable cross-platform frame capture. Set PRODUCER_BROWSER_GPU_MODE=auto to probe hardware availability.",
     },
     quiet: {
       type: "boolean",
@@ -570,8 +570,8 @@ interface RenderOptions {
   gpu: boolean;
   /**
    * Chrome WebGL backend mode. "auto" probes on first launch and falls back
-   * to "software" if no usable GPU. Defaults to "software" when omitted to
-   * stay backwards-compatible with callers that pre-date the tri-state.
+   * to "software" if no usable GPU. Defaults to "software" when omitted for
+   * deterministic local frame capture.
    */
   browserGpuMode?: "auto" | "hardware" | "software";
   hdrMode: "auto" | "force-hdr" | "force-sdr";
@@ -734,12 +734,13 @@ export function validateVariablesAgainstProject(
  *      `--no-browser-gpu` → "software".
  *   3. Env var `PRODUCER_BROWSER_GPU_MODE` accepts "hardware" / "software" /
  *      "auto".
- *   4. Default = "auto" — engine probes WebGL availability on first launch
- *      and falls back to software if the host lacks a usable GPU.
+ *   4. Default = "software" — deterministic SwiftShader capture unless the
+ *      user explicitly opts into host GPU rendering.
  *
- * Returning "auto" by default lets local renders Just Work whether or not the
- * host has a GPU, while preserving the explicit overrides for CI / power
- * users who want failure-on-misconfig.
+ * Plain DOM renders can hit platform-specific GPU compositor bugs on local
+ * Chrome, especially on older Apple Silicon. Keep the default aligned with
+ * the engine's conservative software mode, while preserving explicit hardware
+ * and env-driven auto probing for power users.
  */
 export function resolveBrowserGpuForCli(
   useDocker: boolean,
@@ -750,7 +751,7 @@ export function resolveBrowserGpuForCli(
   if (browserGpuArg === true) return "hardware";
   if (browserGpuArg === false) return "software";
   if (envMode === "hardware" || envMode === "software" || envMode === "auto") return envMode;
-  return "auto";
+  return "software";
 }
 
 const DOCKER_IMAGE_PREFIX = "hyperframes-renderer";

packages/cli/src/docs/rendering.md

@@ -20,13 +20,13 @@ Requires: Docker installed and running.
 - `--crf` — Override encoder CRF (mutually exclusive with `--video-bitrate`)
 - `--video-bitrate` — Target video bitrate such as `10M` (mutually exclusive with `--crf`)
 - `--gpu` — Use GPU encoding (NVENC, VideoToolbox, VAAPI, QSV)
-- `--browser-gpu` / `--no-browser-gpu` — Force host GPU or software (SwiftShader) for Chrome/WebGL capture. Default for local renders is `auto` — probe WebGL availability on first launch and fall back to software if no GPU is reachable. Docker mode always uses software.
+- `--browser-gpu` / `--no-browser-gpu` — Force host GPU or software (SwiftShader) for Chrome/WebGL capture. Local renders default to software for stable cross-platform capture. Set `PRODUCER_BROWSER_GPU_MODE=auto` to probe hardware availability. Docker mode always uses software.
 - `-o, --output` — Custom output path
 
 ## Tips
 
 - Use `draft` quality for fast previews during development
-- Local renders auto-detect GPU on first launch; use `--browser-gpu` to force hardware (errors if no GPU) or `--no-browser-gpu` to force SwiftShader
+- Local renders use software Chrome capture by default; use `--browser-gpu` to force hardware (errors if no GPU) or `PRODUCER_BROWSER_GPU_MODE=auto` to probe and fall back to SwiftShader
 - Use `--gpu` when a local render also benefits from hardware FFmpeg encoding
 - Use `npx hyperframes benchmark` to find optimal settings
 - 4 workers is usually the sweet spot for most compositions