feat(round2+round3): 完整实现 A/B/C/D 主线 + round3-F/H 修复

Round2 主线:
- A: 事件落库地基 (RuntimeApp EventStore 单例 + 14 repo wiring)
- B: 执行体对齐 (read-before-edit, verification-before-completion)
- C: 界面对齐 (@opentui/solid, 删除 runtime 依赖)
- D: 经验闭环 (ExperienceMiner, DebuggerRole, CompactorRole)

Round2 补充修复:
- fail-on-missing 反作弊门禁
- projection-store-apply.test.ts 补写
- 3个空壳测试转行为 (evidence-store, recovery-impl, knowledge-store)
- ask 项目根支持 AIRCODING_PROJECT_ROOT
- Worker 事件契约修复 (task.attempt.started → checkpoint)

Round3-F: cpp 工具切换
- 删除 BuiltInToolRegistrar cpp.* 闭包
- 接入 toolchain-cpp 真实 CppToolRegistrar
- canonical envelope {status/output/metadata}
- ExecutorRole system prompt 对齐新工具名

Round3-H: Doctor 5 类报告
- toolchain (cmake/ninja/cppcheck/clangd/g++)
- display (X11/Wayland + ImageMagick)
- network (internet connectivity)
- provider (api_key/base_url/model/connectivity)

Secret 脱敏:
- 状态交接.md: sk- → \${OPENAI_API_KEY}
- .gitignore: 添加 .air/ .claude/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/cli/src/bootstrap/loadConfig.ts

@@ -30,6 +30,7 @@ const DEFAULT_CONFIG: AirConfig = {
 
 export function loadConfig(project_root?: string): AirConfig {
   let config = { ...DEFAULT_CONFIG }
+  const resolved_project_root = project_root || process.env.AIRCODING_PROJECT_ROOT
 
   // Load global config: ~/.air/config.json
   const global_path = join(homedir(), '.air', 'config.json')
@@ -43,8 +44,8 @@ export function loadConfig(project_root?: string): AirConfig {
   }
 
   // Load project config: .air/local/config.json
-  if (project_root) {
-    const project_path = join(project_root, '.air', 'local', 'config.json')
+  if (resolved_project_root) {
+    const project_path = join(resolved_project_root, '.air', 'local', 'config.json')
     if (existsSync(project_path)) {
       try {
         const project = JSON.parse(readFileSync(project_path, 'utf-8'))
@@ -53,7 +54,7 @@ export function loadConfig(project_root?: string): AirConfig {
         // Ignore malformed project config
       }
     }
-    config.project_root = project_root
+    config.project_root = resolved_project_root
   }
 
   return config