Adds DeepSeek Harness 0.1.2-alpha.3 to the compatibility matrix. No runtime change: the alpha.3 audit found only additive API drift, so this release extends verification only.
- Verifies the views integration bench against Harness 0.1.2-alpha.1, 0.1.2-alpha.2, and 0.1.2-alpha.3 (the bench now supplies the alpha.3 view-selection callbacks the Conversation skeleton requires).
- Adds the 0.1.2-alpha.3 leg to the CI harness matrix.
- Documents the three-alpha matrix in both READMEs.
Verified with 167 standalone tests and 97 Harness integration tests per compatibility target on all three alphas.