docs(plans): add Spec-3 question-gen-v2 implementation plan

9 tasks: type extension → postprocess → families → sampler_v2 →
generator_v2 → gates → run_store → pipeline_v2 → CLI integration.
Includes structured-logging schemas/metrics and Codex review revisions.

research-wiki/log.md

@@ -50,3 +50,18 @@
 - [2026-07-11 15:07 UTC] 新增 plan: Spec-2 建树批量并行实现计划 (plan:batch-tree-build-plan)
 - [2026-07-11 15:07 UTC] 新增边: plan:batch-tree-build-plan --implements--> design:batch-tree-build
 - [2026-07-11 15:07 UTC] 重建索引: 45 篇页面
+- [2026-07-12 02:32 UTC] 新增 schema: 表结构: question_gen_runs（出题批次） (schema:question-gen-runs)
+- [2026-07-12 02:32 UTC] 新增 schema: 表结构: question_gen_items（逐题门判定） (schema:question-gen-items)
+- [2026-07-12 02:33 UTC] 新增 metric: 出题四门总拦截率 (metric:qgen-gate-rejection-rate)
+- [2026-07-12 02:33 UTC] 新增 metric: 重出收敛率（3轮内过门） (metric:qgen-regen-convergence)
+- [2026-07-12 02:33 UTC] 新增 metric: 最终接受率 (metric:qgen-acceptance-rate)
+- [2026-07-12 02:33 UTC] 新增 metric: 答案位置分布均匀性 (metric:qgen-answer-uniformity)
+- [2026-07-12 02:34 UTC] 新增边: metric:qgen-gate-rejection-rate --measures--> schema:question-gen-items
+- [2026-07-12 02:34 UTC] 新增边: metric:qgen-regen-convergence --measures--> schema:question-gen-items
+- [2026-07-12 02:34 UTC] 新增边: metric:qgen-acceptance-rate --measures--> schema:question-gen-runs
+- [2026-07-12 02:34 UTC] 新增边: schema:question-gen-runs --implements--> design:2026-07-11-question-gen-v2
+- [2026-07-12 02:34 UTC] 新增边: schema:question-gen-items --implements--> design:2026-07-11-question-gen-v2
+- [2026-07-12 02:34 UTC] 重建索引: 52 篇页面
+- [2026-07-12 02:38 UTC] 新增 plan: 出题管线 v2 实现计划 (plan:2026-07-11-question-gen-v2)
+- [2026-07-12 02:57 UTC] 新增边: plan:2026-07-11-question-gen-v2 --implements--> design:2026-07-11-question-gen-v2
+- [2026-07-12 02:57 UTC] 重建索引: 53 篇页面