feat(agent): add static runtime preflight

[zpzjzj]

Summary

• run binary availability and static version checks before each case without probing authentication
• enforce exact configured CLI versions for supported isolated adapters while never modifying runtime: none hosts
• record requested, applied, and observed versions in JSON, Markdown, and HTML reports

Compatibility

• local login remains delegated to the CLI; preflight makes no authentication or model request
• QoderCLI versions are observed, while engine.version remains unsupported and is ignored
• historical YAML, CLI override, and GitHub Action behavior remains compatible

Validation

• make verify
• make test
• make test-action
• make build
• go test -tags e2e -v -parallel 1 ./e2e

Part of #196 (PR 5).

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-04T04:58:44.095762Z	e19c008	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[JHWang-1997]

Before this change, a v1alpha1 config using engine.version values such as latest or ^1.2.0 passed validation and ran with a warning. The same config now fails for Claude Code, Codex, and Qwen Code, which seems inconsistent with the compatibility statement and the acceptance criteria in #196. Could we keep the previous warn-and-ignore behavior for non-exact versions, or explicitly document this as a breaking change with a migration path?