v0.3.1 -- Phase-7 review fixes

v0.3.1 -- Phase-7 review fixes (intersection P0s)

Three-way Phase-7 review of v0.3.0 (correctness + test-quality +
architecture lenses) caught five issues single-author construction
had missed. The loud one: the CHANGELOG claim "ALL THREE analysts
shipped" was structurally FALSE -- the advisor hard-coded two analysts
and never instantiated KronosAnalyst for live ticks. v0.3.1 closes that
plus the BMA abstain-filter contract from ADR-0018 D4.

Highlights

• BMA abstain filter wired (ADR-0018 D4): views with confidence < 0.10
  dropped before aggregation. Closes the bug where Kronos's zero-confidence
  abstain (on missing kronos package) inflated silence-bias gate
  voice-count.
• Advisor loads KronosAnalyst as third voice -- the charter MVP recipe
  now actually delivered for live ticks.
• KairosAnalyst phantom entry-point removed (would have broken plug-and-
  play install discovery).
• Lookahead CI gate rewired to canonical evaluation.lookahead module
  (Wave-D follow-up v0.3.0 didn't complete).
• KronosConfig deterministic_seed=42 for charter "every signal replayable
  from disk" invariant.

Test sweep: 506 passed, 1 skipped (was 494 -> +12, zero regressions).

Phase-7 review artifacts on disk at docs/reviews/2026-05-13-v030/:
correctness.md + test-quality.md + architecture.md. 16 P1/P2 items
explicitly deferred to v0.3.2+ (CHANGELOG enumerates).