mode: static with no repos should not require workspace.path

[christso]

Problem

When workspace.mode=static is set but workspace.path is empty/unset and there are no repos, agentv errors with:

workspace.mode=static requires workspace.path or --workspace-path

This is counter-intuitive. If there are no repos to materialize, mode: static should work without a path — agentv could create a temp directory just like it does when mode is not specified.

Repro

# evals/mygroup/.templates/eval-workspace-setup.yaml
path: ${{ SOME_UNSET_ENV_VAR }}
mode: static
hooks:
  before_all:
    command:
      - node
      - ../../../scripts/eval-config/copy-local-skills.mjs
      - --plugin
      - my-plugin
# no repos section

# evals/mygroup/my-eval.eval.yaml
workspace: .templates/eval-workspace-setup.yaml
tests:
  - id: test1
    input: hello

agentv eval run evals/mygroup/my-eval.eval.yaml
# Error: workspace.mode=static requires workspace.path or --workspace-path

Expected

When mode: static is set with no repos and no path, agentv should treat it the same as when mode is omitted — create a temp workspace directory and proceed. The static mode's purpose is to skip repo cloning, which is already a no-op when there are no repos.

Workaround

Remove path and mode: static from templates that have no repos.