`openers` config: allow extra CLI args for the `claude` (and other attach-dirs) opener, e.g. `--dangerously-skip-permissions`

[ChampPABA]

What I'm trying to do

Use openspec workset open <name> --tool claude to launch a Claude Code
session with several repos attached (--dir per member), so an agent
working on a cross-repo feature (spec lives in a planning store, code lives
in several separate component repos) can see and edit all of them in one
session.

What's missing

The documented openers schema (docs/cli.md) only supports two fields
per tool:

{
  "openers": {
    "zed": { "style": "workspace-file" },
    "claude": { "attach_flag": "--dir" }
  }
}

There's no way to pass additional static CLI flags to the launched binary.
Concretely, I want workset open to launch Claude Code with
--dangerously-skip-permissions (and potentially other flags in the
future), but the attach_flag field only controls the per-member
attachment flag, not extra one-time flags for the tool itself.

Proposed fix

Add an optional field, e.g. extra_args: string[], to the attach-dirs
opener shape:

{
  "openers": {
    "claude": {
      "attach_flag": "--dir",
      "extra_args": ["--dangerously-skip-permissions"]
    }
  }
}

workset open would append extra_args to the launch command after the
--dir <member> flags.

Workaround I'm using today

Not using workset open for this case — copying the member paths from
openspec workset list and launching manually:

claude --dangerously-skip-permissions \
  --dir <store> --dir <repo-a> --dir <repo-b>

Works fine, just loses the one-command convenience workset open is meant
to provide.

Version: @fission-ai/openspec@1.5.0 (checked schema against v1.6.0
release notes/docs too — same openers shape as of that release)

Related: #1257 describes the same multi-repo store setup (one planning
store, several component repos) that led me here — different ask (docs
example vs. this config gap), but same underlying use case.

[ChampPABA]

Closing this: the capability already exists, I just could not see it from the docs.

The openers row schema in src/core/openers.ts accepts args (pre-args placed before the attach pairs), not only style and attach_flag. So this works today, no new field needed:

{
  "openers": {
    "claude": { "args": ["--dangerously-skip-permissions"] }
  }
}

which launches:

claude --dangerously-skip-permissions --add-dir /path/a --add-dir /path/b

The built-in codex opener already relies on this to ship --sandbox workspace-write, so extra_args would have duplicated a tested field.

Worth noting for anyone landing here: attach-dirs openers (claude, codex) are gated off by default right now, so workset open --tool claude errors with "temporarily disabled while CLI-agent opening is reworked" regardless of config.

Opened #1356 to document the full field list in docs/cli.md so the next person does not file this again.