Adds GET /config_tester/dashboard (SPA as a top-level page, optional
?session=), POST /config_tester/run (builds the Generator -> Dashboard prompt
and enqueues it in-process exactly like PromptServer.post_prompt; force
defaults to true) and GET /config_tester/run_status. Pure helpers live in
run_api.py (no server imports) with unit tests.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
