v2.0.5 — Same-family second-opinion judge guard

Patch release. Adds a stdlib-only same-family judge guard plus a
self_preference_risk scorecard flag to the opt-in LLM second-opinion
analyzer.

Added

• Same-family judge guard (skills/judge/analyzers/llm_judge.py):
  new model_family() (prefix-buckets a model ID into
  anthropic/openai/google/meta) and same_family_guard(). Before the
  opt-in second opinion runs, the guard compares the executing model
  (from score.detect_model_from_transcript) against the configured
  judge model. On a same-family match it (a) sets
  self_preference_risk: true on the scorecard and emits a
  Verdict WARNING: line on stderr citing the measured effect
  (MT-Bench: GPT-4 +10%, Claude-v1 +25% self-win-rate), and (b) when a
  cross-family llm_second_opinion.alternate_judge_models entry is
  configured, auto-prefers it for the call (reachable via the
  documented injected-client / proxy path). Off-by-default with the
  rest of the second opinion; stdlib-only, no new deps.
• self_preference_risk (boolean) and same_family_guard (object)
  optional top-level scorecard fields — additive, backward-compatible
  in schemas/scorecard.v1.schema.json.
• llm_second_opinion.alternate_judge_models config key (default []).
• tests/test_same_family_guard.py: family bucketing, same-family
  risk + citation, cross-family clear, auto-prefer substitution,
  build_scorecard integration via a mock client, and a regression
  assertion that build_prompt / SYSTEM_PROMPT never use
  first-person framing ("you wrote" / "your work" / "your output").

Rationale

An LLM judge over-scores its own family. The effect is measured, not
hypothetical (self-preference: arXiv:2306.05685; role-relabel framing
swings scores +23–93pp: arXiv:2606.05976), and in Verdict's stock
configuration the second opinion is Claude-judging-Claude — so the
guard fires on every enabled run, which is the honest signal. The
existing third-party "second-opinion judge" framing is preserved.