refactor: Provider 拍平到 d2x/buildtools(去掉冗余的 mcpp 目录层)

Author: Sunrisepeak

.agents/docs/2026-07-23-exercises-as-tests-reference.md

@@ -11,9 +11,9 @@
 ## 1. 布局（第二轮重排后：库入驻 d2x/、课程收进 src/）
 
 ```
-mcpp.toml                 workspace = [d2x, src/*, src/en/*, d2x/buildtools/mcpp]
+mcpp.toml                 workspace = [d2x, src/*, src/en/*, d2x/buildtools]
 d2x/                      d2x 练习库(纯模块 `import d2x;`,零宏)
-d2x/buildtools/mcpp/      Provider(C++26)
+d2x/buildtools/      Provider(C++26)
 src/intro/tests/hello-mcpp.cpp
 src/cpp11/tests/<NN-topic>/<K>.cpp    49 题
 src/cpp14/tests/00-generic-lambdas/{0,1}.cpp
@@ -79,7 +79,7 @@ Provider 只是把 mcpp 的 JSON 记录 × 侧信道合并成协议 verdict。
 
 | 项 | 结果 |
 |---|---|
-| e2e（`d2x/buildtools/mcpp/tests/e2e.sh all`） | zh 52/52、en 52/52 答案全绿；pristine 双向 0-pass；Provider 冒烟 ✓ |
+| e2e（`d2x/buildtools/tests/e2e.sh all`） | zh 52/52、en 52/52 答案全绿；pristine 双向 0-pass；Provider 冒烟 ✓ |
 | d2x 端到端 | checker 显示 0/52 → 改对自动推进 → state.json 兼容旧 id ✓ |
 | d2x 仓库改动 | **零**（协议边界承诺兑现） |
 | hello-mcpp | 答案已补，进入 e2e，不再 SKIP |

.agents/skills/d2mcpp-authoring/references/anatomy.md

@@ -47,7 +47,7 @@ Features`).
 **Exercises are tests.** Each `<std>/` is a real mcpp project and exercises are
 its `tests/`; dropping `<std>/tests/NN-topic/K.cpp` into place is the whole job.
 `mcpp test -p src/<std>` runs them natively (the report is the progress table), and
-the d2x Provider (`d2x/buildtools/mcpp/`) derives the exercise id, order and
+the d2x Provider (`d2x/buildtools/`) derives the exercise id, order and
 chapter from the same path — one chain, no generated manifests, nothing under
 `.d2x/` but learner progress.
 
@@ -81,7 +81,7 @@ change compile flags.
 
 Drop the file at `solutions/<std>/NN-topic/K.cpp` (zh/en share one solution).
 CI swaps it over the exercise and asserts it passes; see
-`d2x/buildtools/mcpp/tests/e2e.sh`.
+`d2x/buildtools/tests/e2e.sh`.
 
 ## SUMMARY registration
 
@@ -114,10 +114,10 @@ Run from the project root; report real output, do not assert success blind:
 mcpp test -p src/<std> NN-topic
 
 # check it through the Provider path (exactly what `d2x checker` consumes)
-mcpp run -q -p d2x/buildtools/mcpp -- check cppNN-NN-topic-0
+mcpp run -q -p d2x/buildtools -- check cppNN-NN-topic-0
 
 # or validate every exercise + solution at once (zh + en)
-bash d2x/buildtools/mcpp/tests/e2e.sh all
+bash d2x/buildtools/tests/e2e.sh all
 
 # drive the auto-checker against the exercise (expects the unsolved exercise to fail,
 # the solution to pass) — name omits the NN- prefix

.d2x.json

@@ -1,6 +1,6 @@
 {
     "version": "0.1.1",
-    "buildtools": "mcpp run -q -p d2x/buildtools/mcpp --",
+    "buildtools": "mcpp run -q -p d2x/buildtools --",
     "lang": "zh",
     "llm": {
         "api_key": "",

.github/workflows/dslings-ref-ci.yml

@@ -60,10 +60,10 @@ jobs:
           xlings install -y
 
       - name: Build d2x Provider
-        run: mcpp build -p d2x/buildtools/mcpp
+        run: mcpp build -p d2x/buildtools
 
       - name: Validate exercises and solutions (zh + en)
-        run: bash d2x/buildtools/mcpp/tests/e2e.sh all
+        run: bash d2x/buildtools/tests/e2e.sh all
 
       - name: Verify exercises ↔ solutions filename parity
         run: |

book/en/src/base/chapter_1.md

@@ -163,7 +163,7 @@ Edit the `lang` attribute in the project configuration file `.d2x.json`. `zh` co
 ```bash
 {
     "version": "0.1.1",
-    "buildtools": "mcpp run -q -p d2x/buildtools/mcpp --",
+    "buildtools": "mcpp run -q -p d2x/buildtools --",
     "lang": "en",
     ...
 }
@@ -177,7 +177,7 @@ If you prefer to use Neovim as your editor with LSP (clangd) support, you can co
 
 ```json
 {
-    "buildtools": "mcpp run -q -p d2x/buildtools/mcpp --",
+    "buildtools": "mcpp run -q -p d2x/buildtools --",
     "editor": "nvim",
     ...
 }

book/src/base/chapter_1.md

@@ -161,7 +161,7 @@ Homepage: https://github.com/openxlings/xlings
 ```bash
 {
     "version": "0.1.1",
-    "buildtools": "mcpp run -q -p d2x/buildtools/mcpp --",
+    "buildtools": "mcpp run -q -p d2x/buildtools --",
     "lang": "en",  < -- 修改这里
     ...
 }
@@ -175,7 +175,7 @@ Homepage: https://github.com/openxlings/xlings
 
 ```json
 {
-    "buildtools": "mcpp run -q -p d2x/buildtools/mcpp --",
+    "buildtools": "mcpp run -q -p d2x/buildtools --",
     "editor": "nvim",
     ...
 }

d2x/buildtools/mcpp/mcpp.toml d2x/buildtools/mcpp.tomld2x/buildtools/mcpp/mcpp.toml renamed to d2x/buildtools/mcpp.toml

@@ -1,5 +1,5 @@
 [package]
-name        = "d2x-buildtools-mcpp"
+name        = "d2x-buildtools"
 version     = "0.1.0"
 description = "d2mcpp 的 d2x Provider：枚举练习、生成 mcpp 清单、构建/运行/判定"
 license     = "Apache-2.0"

d2x/buildtools/mcpp/src/discovery.cppm d2x/buildtools/src/discovery.cppmd2x/buildtools/mcpp/src/discovery.cppm renamed to d2x/buildtools/src/discovery.cppm

@@ -13,7 +13,7 @@
 // 走的是完全相同的链路，不存在平行路径。
 //
 // 用法（由 .d2x.json 的 buildtools 字段驱动，从仓库根执行，无需 cd）：
-//   mcpp run -q -p d2x/buildtools/mcpp -- check cpp11-00-auto-and-decltype-0
+//   mcpp run -q -p d2x/buildtools -- check cpp11-00-auto-and-decltype-0
 
 import std;