docs(decisions): record eval runner extraction boundary

[BjRo]

Why

Issue #209 starts the staged extraction tracked by #95 by recording the durable repository boundary before any runner migration. Closes #209.

What changed

Added ADR-0010 to assign generic evaluation infrastructure to the versioned Sevro package while Darrow retains its evaluation policy, cases, and product integration. Marked ADR-0001 as superseded and rebuilt the ADR catalog; specifications, eval fixtures, runner code, and plugin content are unchanged.

Verification

All passed:

• bun run check:decisions
• bun run check:docs
• bun run check:docs:external
• bun run lint
• bun run lint:ts
• bun run lint:shell
• bun run typecheck
• bun run check:python
• darrow-decision catalog check --dir "$PWD/docs/decisions"
• darrow-decision validate --dir "$PWD/docs/decisions"

Review notes

This PR changes no runtime or capability behavior. Package naming and registry details, extension transport and framing, public JSON schemas, and CLI exit-code mapping remain follow-up decisions under #95.

Checklist

• I have read and followed CONTRIBUTING.md, including the contribution
  licensing terms.
• I added or updated the applicable invariant before implementation, or
  this change does not affect a capability invariant.
• I added or updated colocated evals, or this change does not affect skill
  behavior.
• I confirmed that each changed plugin remains self-contained, or this
  change does not affect plugin content.
• I ran bun run check:python, or this change does not affect registered
  Python packages or their repository quality infrastructure.