Bug: (eval):1: unknown file attribute: h

I recently updated mise to the latest version with `mise self-update`

```
• mise version
_ __
____ ___ (_)_______ ___ ____ ____ / /___ _________
/ __ `__ \/ / ___/ _ \______/ _ \/ __ \______/ __ \/ / __ `/ ___/ _ \
/ / / / / / (__ ) __/_____/ __/ / / /_____/ /_/ / / /_/ / /__/ __/
/_/ /_/ /_/_/____/\___/ \___/_/ /_/ / .___/_/\__,_/\___/\___/
/_/ by @jdx
2026.7.17 macos-arm64 (2026-07-30)
```

This had the effect of breaking all of my tab completion, I started seeing these errors:

```
• mise run //[WARN usage::spec] This usage spec requires at least version 4.0, but you are using version 3.5.6 of usage
× Invalid usage config
╭─[/var/folders/wb/1hxcm9js0zd0sfgkj4r3959c0000gn/T//usage__usage_spec_mise_2025_11_4.spec:96:67]
95 │ arg "[-- TASK_ARGS_LAST]…" required=#false var=#true hide=#true
96 │ cmd activate help="Initializes mise in the current shell session" effect=read {
· ─────┬─────
· ╰── unsupported cmd prop effect
97 │ long_help #"""
```

So I updated to `usage @ v4.0.0`

```
• mise use -g usage@v4.0.0
[...]
• usage --version
usage-cli 4.0.0
• which usage
/Users/pd/.local/share/mise/installs/usage/v4.0.0/usage
```

But now when I tab-complete, I get a different error. If I type `mise run `, I see:

```
• mise run mise run
(eval):1: unknown file attribute: h
```

The duplicate `mise run mise run` is what the `` completes to.

Reproduce the failure with `mise run ` after installing `usage@v4.0.0`, and compare it with the earlier usage 3.5.6 error. Trace the CLI completion path and shell evaluation that produces the duplicate `mise run mise run` and `(eval):1: unknown file attribute: h`. Done means completion emits the intended command without either error.

Written by the indexing model from the issue text.