Add triangle prism chamfer adjacency parity lab, tests, and docs

[yuechen-li-dev]

Motivation

• Provide a deterministic lab to compare legacy triangular prism construction against a LineArcProfileExtrudeEmitter candidate specifically for downstream bounded chamfer/corner recognition parity.
• Capture detailed adjacency and vertex/edge diagnostic rows and bounded-chamfer admissibility to drive a safe production migration decision after V2-V5 reverted for chamfer regressions.
• Emit deterministic diagnostics, first-divergence classification, and a recommendation/blocker classification to make next steps explicit.

Description

• Add TrianglePrismChamferAdjacencyParityLab which constructs legacy and candidate triangle prisms, summarizes adjacency (SummarizeAdjacency) and corner chamfer candidate outcomes (SummarizeCornerCandidates), and emits per-case parity rows and diagnostics.
• Introduce TrianglePrismChamferAdjacencyParityLabTests with deterministic and parity/assertion checks that call TrianglePrismChamferAdjacencyParityLab.RunAll() and validate diagnostics and recommendations.
• Add documentation docs/frictionlab/v2-x8-1-triangle-chamfer-adjacency-parity-lab.md describing the lab purpose, cases, findings, and recommended next steps, and update related docs to reference the new lab.

Testing

• Added unit tests in Aetheris.FrictionLab.Tests under TrianglePrismChamferAdjacencyParityLabTests and ran them with dotnet test, and the tests passed.
• The tests exercise determinism via RunAll() and parity/diagnostic assertions and confirmed stable, non-empty adjacency and chamfer diagnostic outputs.

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Codex Task