feat: D16 adjudication — 2v2 stays hypothesis until a rule fires

[eSlider]

Summary

• D16: ≥2 yes vs ≥2 no stays (not confirmed) until temporal_freshness or authority_pairing fires (internal/facts, bin/facts/audit contradict).
• Hypothesis facts escalate to web; confirmed facts do not. Search returns confidence.
• Gitea #29. Do not close GitHub feat: incremental brain/add without rebuild (#14) #29.

Test plan

• go test ./internal/facts ./internal/brain/rank -count=1
• CC=gcc CXX=g++ CGO_CFLAGS= CGO_LDFLAGS= go test ./... -count=1
• uv run python -m unittest bin.tools.test_contradict bin.tools.test_bin_layout -q
• ./bin/facts/audit self
• echo '{"text":"x","yes":[{"id":"a","kind":"runtime"},{"id":"b","kind":"config"}],"no":[{"id":"c","kind":"runtime"},{"id":"d","kind":"config"}]}' | ./bin/facts/audit contradict --json → unresolved
• GitHub Actions Test + OCR green

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