feat(sdk): 通用反代声明项（DeclareProxy）+ ToolDef.Serial 串行标记 + 场面策略文档

本次一并提交工作区此前累积的改动（均已验证），并接入工具并发调度所需的
声明项。

把「谁来反代谁」从内核硬编码变成插件可声明。设备网关（remotedevice）
这类**编译进内核、没有独立插件目录与 plugin.json** 的服务，静态扫描扫不到，
此前只能靠约定。新增 DeclareProxy 让它们能自己声明反代路由。

ParallelSafe 的**反向**声明项。判据优先级：Serial 胜出，显式声明不允许被
ParallelSafe 或任何默认值覆盖。

为什么需要它：ParallelSafe 零值 false 已表达「安全/串行」，插件无法区分
「我没想过」和「我确认过必须串行」。没有这个区分，工具作者只能靠命名约定
传递意图，那不是契约。

ParallelSafe 本身也补齐了注释，明确其零值语义（默认串行、保守）与理由
（新语义下并发会改变工具的行为前提，让存量插件意外并发比慢一点危险得多）。

配套 ScenePolicy 声明项的使用说明。

remotedevice/ 整目录（C 实现的设备网关，已由 Go 侧 DeclareProxy 路径取代）。

- sdk/knowledge.go：随场面策略配套调整
- docs/api/*、docs/assets/api-index.json、docs/llms.txt、mkdocs.yml：
  由 tools/apidoc/build.sh 从源码重新生成（行号随 plugin.go 变动漂移）

remotedevice/CMakeLists.txt

@@ -1,116 +0,0 @@
-cmake_minimum_required(VERSION 3.10)
-project(ha_remotedevice VERSION 0.1.0 LANGUAGES C)
-
-# ============================================================
-# ha_remotedevice — HomeAgent 远程设备接入 C SDK
-# 零外部依赖，纯 C 实现，兼容嵌入式平台。
-#
-# 使用方式:
-#   add_subdirectory(path/to/ha_remotedevice)
-#   target_link_libraries(my_app ha_remotedevice)
-#   target_include_directories(my_app PRIVATE
-#     ${HA_REMOTEDEVICE_INCLUDE_DIR})
-# ============================================================
-
-# 选项: 构建为静态库或动态库
-option(BUILD_SHARED_LIBS "Build ha_remotedevice as shared library" OFF)
-
-# 选项: 禁用 malloc/free（用于裸机环境，用户需提供 alloc 回调）
-option(HA_NO_ALLOC  "Disable dynamic memory allocation" OFF)
-
-# 选项: 日志级别
-set(HA_LOG_LEVEL 2 CACHE STRING "Log level: 0=none, 1=error, 2=info, 3=debug")
-
-# 源文件
-set(HA_REMOTEDEVICE_SRC
-    src/ha_remotedevice.c
-    src/ha_json.c
-    src/ha_ws.c
-)
-
-# 头文件
-set(HA_REMOTEDEVICE_INCLUDE
-    ${CMAKE_CURRENT_SOURCE_DIR}/include
-)
-
-# 编译选项
-if(HA_NO_ALLOC)
-    add_definitions(-DHA_NO_ALLOC)
-endif()
-add_definitions(-DHA_LOG_LEVEL=${HA_LOG_LEVEL})
-
-# 创建库
-if(BUILD_SHARED_LIBS)
-    add_library(ha_remotedevice SHARED ${HA_REMOTEDEVICE_SRC})
-    if(WIN32)
-        # Windows 需要导出符号
-        set_target_properties(ha_remotedevice PROPERTIES
-            WINDOWS_EXPORT_ALL_SYMBOLS ON)
-    endif()
-else()
-    add_library(ha_remotedevice STATIC ${HA_REMOTEDEVICE_SRC})
-endif()
-
-# 包含目录
-target_include_directories(ha_remotedevice
-    PUBLIC  ${HA_REMOTEDEVICE_INCLUDE}
-    PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src
-)
-
-# 不链接任何外部库
-target_link_libraries(ha_remotedevice PRIVATE)
-
-# 导出包含目录供外部项目使用
-set(HA_REMOTEDEVICE_INCLUDE_DIR
-    ${HA_REMOTEDEVICE_INCLUDE}
-    CACHE INTERNAL "ha_remotedevice include directories")
-
-# 安装规则
-install(TARGETS ha_remotedevice
-    EXPORT  ha_remotedevice-targets
-    LIBRARY DESTINATION lib
-    ARCHIVE DESTINATION lib
-    RUNTIME DESTINATION bin
-    INCLUDES DESTINATION include
-)
-
-install(DIRECTORY include/
-    DESTINATION include
-)
-
-install(EXPORT ha_remotedevice-targets
-    DESTINATION lib/cmake/ha_remotedevice
-    NAMESPACE ha_remotedevice::
-)
-
-# ============================================================
-# 测试（可选）
-# ============================================================
-option(BUILD_TESTS "Build ha_remotedevice tests" OFF)
-
-if(BUILD_TESTS)
-    find_package(Threads REQUIRED)
-
-    add_executable(ha_remotedevice_test
-        test/test_ha_remotedevice.c
-    )
-    target_link_libraries(ha_remotedevice_test
-        PRIVATE ha_remotedevice Threads::Threads
-    )
-    target_include_directories(ha_remotedevice_test
-        PRIVATE ${HA_REMOTEDEVICE_INCLUDE_DIR}
-    )
-
-    # 添加测试
-    add_test(NAME ha_remotedevice_test
-        COMMAND ha_remotedevice_test
-    )
-endif()
-
-# ============================================================
-# 编译信息
-# ============================================================
-message(STATUS "ha_remotedevice ${PROJECT_VERSION}")
-message(STATUS "  Build type: $<CONFIG>")
-message(STATUS "  Shared lib: ${BUILD_SHARED_LIBS}")
-message(STATUS "  No alloc:   ${HA_NO_ALLOC}")