docs: plan the sampling parameter implementation (issue #4)

Eleven verifiable tasks covering decisions A-G and the 14 test items,
with the reviewer-found execution traps written into the tasks.

research-wiki/index.md

@@ -1,6 +1,6 @@
 # Research Wiki 索引
 
-> 自动生成，更新时间：2026-07-31 16:31 UTC
+> 自动生成，更新时间：2026-07-31 17:01 UTC
 
 ## design (20)
 - [2026-07-20-m1-core-design](designs/2026-07-20-m1-core-design.md) `design:2026-07-20-m1-core-design`
@@ -37,7 +37,7 @@
 - [P6 混合浸泡首跑基线与记分板三重伪击穿修复](findings/p6-soak-baseline.md) `finding:p6-soak-baseline`
 - [P7 OCR soak 验收: 99.73% 与 13 不变量全 PASS](findings/p7-ocr-soak.md) `finding:p7-ocr-soak`
 
-## plan (14)
+## plan (16)
 - [2026-07-20-m1-core-plan](plans/2026-07-20-m1-core-plan.md) `plan:2026-07-20-m1-core-plan`
 - [2026-07-20-m2-distributed-plan](plans/2026-07-20-m2-distributed-plan.md) `plan:2026-07-20-m2-distributed-plan`
 - [2026-07-21-m25-resilience-plan](plans/2026-07-21-m25-resilience-plan.md) `plan:2026-07-21-m25-resilience-plan`
@@ -45,6 +45,7 @@
 - [2026-07-22-m4-migration-plan](plans/2026-07-22-m4-migration-plan.md) `plan:2026-07-22-m4-migration-plan`
 - [2026-07-30-est-tokens-decoupling-plan](plans/2026-07-30-est-tokens-decoupling-plan.md) `plan:2026-07-30-est-tokens-decoupling-plan`
 - [2026-07-31-response-observability-fields](plans/2026-07-31-response-observability-fields.md) `plan:2026-07-31-response-observability-fields`
+- [2026-07-31-sampling-params](plans/2026-07-31-sampling-params.md) `plan:2026-07-31-sampling-params`
 - [est_tokens 解耦实施计划](plans/est-tokens-decoupling.md) `plan:est-tokens-decoupling`
 - [M1 核心里程碑实现计划](plans/m1-core-plan.md) `plan:m1-core-plan`
 - [M2 分布式实现计划](plans/m2-distributed.md) `plan:m2-distributed`
@@ -52,6 +53,7 @@
 - [M3 OCR 实现计划](plans/m3-ocr.md) `plan:m3-ocr`
 - [M4 迁移实现计划(T0-T14)](plans/m4-migration.md) `plan:m4-migration`
 - [响应可观测字段扩展实现计划](plans/response-observability-fields.md) `plan:response-observability-fields`
+- [采样参数透传实现计划(issue #4)](plans/sampling-params-plan.md) `plan:sampling-params-plan`
 
 ## schema (1)
 - [表结构: llm_calls(遥测 20 字段)](schemas/llm-calls.md) `schema:llm-calls`