Introduce testEnvironment() on ServerAdapterModule with structured
pass/warn/fail diagnostics for all four adapter types (claude_local,
codex_local, process, http). Adds POST test-environment endpoint,
shared types/validators, adapter test implementations, and UI API
client. Includes asset type foundations used by related features.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Move doc/specs/ui.md to doc/spec/ui.md. Move plans/module-system.md to
doc/plans/. Add doc/spec/agents-runtime.md and docs/ reference specs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>