Release pisama 0.7.0: explicit assessment coverage

[tn-pisama]

Prepare 0.7.0 following merged assessment coverage PR28. Includes schema-3 migration notes, explicit detector-error exit behavior, and honest unknown/abstained coverage. Local verification: 228 tests, lint, mypy, and fresh wheel/sdist consumers with public core 1.10.3 and pending core eeaa7a3. This version bump does not publish the pending core correction or claim calibrated accuracy. Release publication remains gated on CI and artifact verification.

[tn-pisama]

Release hold: an additional installed-artifact audit reproduced misleading completeness on a two-span trace with one checked JSON contract and one unsupported request. Count-only completeness also accepts duplicate detector assessment identities. This candidate must not be merged or published until reporting semantics and regressions are corrected and independently verified. CI success alone does not clear this hold.

[tn-pisama]

Updated to 7e2ec68 after merged corrective PR30 (14c40de). Tree exactly matches independently prepared candidate2c9ee92; root reproduced 250 paired tests and installed wheel/sdist mixed-trace accounting. New CI is required. The earlier completeness/cross-consistency blockers are corrected; publication remains held until this updated candidate passes every release gate.