feat(selector): 增加离线候选遍历与严格回放验证 Demo

- 新增 selector_candidate_demo，移除 provenance intent 后枚举候选 selector
- 对候选分支执行有界重建与严格 STEP 比较
- 仅在候选遍历完整且唯一 strict 通过时生成 selector 映射记录
- 增加 selector 候选搜索、预算限制和记录生成的测试
- 保持生产 selector resolver 不受 Demo 逻辑影响
- 更新 CADFS 能力台账，记录 IMPRINT 派生 profile 的 lineage selector 缺口

cadfs_to_cdsl/ir.py

@@ -41,3 +41,5 @@ class ModelIR:
     # selector can be audited against the FeatureScript API contract it used.
     featurescript_version: str | None = None
     standard_library: str | None = None
+    standard_library_version: str | None = None
+    standard_library_imports: list[dict[str, str]] = field(default_factory=list)