build from-workflow prints a --json invocation the CLI refuses

`comfy build from-workflow` tells the caller how to pin `baseComfyVersion` when the import comes back with `comfyVersionRequired: true`. The command it prints does not run.

**What it prints** (`comfy_cli/command/distribution.py`, `from_workflow_cmd`):

```
comfy build get --json | jq .data.definition > def.json
```

**What that does:**

```
$ comfy build get 42014768-dd52-4d37-82f5-821ef6e141e8 --json
Usage: comfy build get [OPTIONS] BUILD_ID
Error: No such option: --json
```

`--json` is a root-level option, so it has to precede the group:

```
$ comfy --json build get 42014768-dd52-4d37-82f5-821ef6e141e8
{"schema": "envelope/1", ..., "command": "build get", ...}
```

**Why it matters:** a workflow names no ComfyUI version, so `comfyVersionRequired` is true on every fresh import, which makes this hint the standard next step rather than an edge case. A caller who follows it hits a usage error on the one instruction that unblocks the cut.

**Fix:** print `comfy --json build get | jq .data.definition > def.json`.

Found while writing the comfy-build skill's workflow path against this verb.