Add a Runner Eval

Use this skill for the Runner Evals family: a real Runner/provider session against a seeded mock control plane. Product browser/server/database/Daytona coverage belongs in add-product-e2e-eval.

Locate the Paperclip checkout using PAPERCLIP_ROOT when supplied, or git rev-parse --show-toplevel from a checkout. From outside Git, inspect the workspace roots (for example ~/paperclipai/paperclip) and verify that the selected root contains packages/paperclip-runner and tests/runner-e2e. Locate paperclip-evals using PAPERCLIP_EVALS_ROOT or a discovered sibling; a worktree's parent directory need not contain that repository. Read doc/evals.md and packages/paperclip-runner/docs/runner-protocol-live-evals.md, then inspect the nearest existing case, roster, schema, and report test before editing. Definitions and authored cases belong in the sibling paperclip-evals/evals/paperclip-runner; Runner integration, aggregation, viewer, and publication behavior belongs in packages/paperclip-runner. Keep the control-plane boundary explicit in names and documentation.