Initial dstalk project: core DLL + CLI + BearSSL TLS

- Core DLL: AI API client (DeepSeek/OpenAI compatible), HTTP(S) via Boost.Beast
- BearSSL vendored as TLS backend (MIT license, replacing OpenSSL)
- CLI frontend with ANSI colors, /help /model /file /save /load commands
- WinHTTP alternative HTTP client for Windows
- GPLv3 license with linking exception
- Build: CMake + Ninja + Clang, dependencies via Conan2

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

build.bat

@@ -0,0 +1,107 @@
+@echo off
+chcp 65001 >nul
+setlocal enabledelayedexpansion
+
+set "ROOT=%~dp0"
+set "TOOLS=%ROOT%tools\"
+
+:: ============================================================
+:: 1. 检查 tools\ 工具链
+:: ============================================================
+echo [dstalk] 检查工具链...
+
+if not exist "%TOOLS%cmake\bin\cmake.exe" (
+    echo   [ERROR] CMake 未找到，请先运行: tools\setup.bat
+    pause & exit /b 1
+)
+if not exist "%TOOLS%ninja\ninja.exe" (
+    echo   [ERROR] Ninja 未找到，请先运行: tools\setup.bat
+    pause & exit /b 1
+)
+if not exist "%TOOLS%llvm\bin\clang.exe" (
+    echo   [ERROR] LLVM/Clang 未找到，请先运行: tools\setup.bat
+    pause & exit /b 1
+)
+if not exist "%TOOLS%conan2\conan.exe" (
+    echo   [ERROR] Conan2 未找到，请先运行: tools\setup.bat
+    pause & exit /b 1
+)
+
+:: ============================================================
+:: 2. 加载 tools\ 环境
+:: ============================================================
+call "%TOOLS%env.bat"
+
+:: ============================================================
+:: 3. 检测并加载 MSVC 环境
+:: ============================================================
+set "VCVARS="
+for %%v in (2022 2019 2017) do (
+    for %%e in (Professional Community Enterprise BuildTools) do (
+        if exist "C:\Program Files (x86)\Microsoft Visual Studio\%%v\%%e\VC\Auxiliary\Build\vcvarsall.bat" (
+            set "VCVARS=C:\Program Files (x86)\Microsoft Visual Studio\%%v\%%e\VC\Auxiliary\Build\vcvarsall.bat"
+        )
+        if exist "C:\Program Files\Microsoft Visual Studio\%%v\%%e\VC\Auxiliary\Build\vcvarsall.bat" (
+            set "VCVARS=C:\Program Files\Microsoft Visual Studio\%%v\%%e\VC\Auxiliary\Build\vcvarsall.bat"
+        )
+    )
+)
+
+if "%VCVARS%"=="" (
+    echo   [ERROR] 未找到 Visual Studio Build Tools
+    echo   请安装: https://visualstudio.microsoft.com/downloads/#build-tools-for-visual-studio-2022
+    pause & exit /b 1
+)
+echo [dstalk] 加载 MSVC 环境...
+call "%VCVARS%" x64 >nul 2>&1
+
+:: ============================================================
+:: 4. 强制使用 tools\ 内的编译器 (覆盖 MSVC 的 cl.exe)
+:: ============================================================
+set "CC=%TOOLS%llvm\bin\clang.exe"
+set "CXX=%TOOLS%llvm\bin\clang++.exe"
+
+cd /d "%ROOT%"
+
+:: ============================================================
+:: 5. Conan 安装依赖
+:: ============================================================
+if not exist "%ROOT%build\conan_toolchain.cmake" (
+    echo [dstalk] Conan 安装依赖...
+    call "%TOOLS%conan2\conan.exe" install deps/ -of build --build=missing
+    if !errorlevel! neq 0 (
+        echo   [ERROR] Conan 安装失败
+        pause & exit /b 1
+    )
+) else (
+    echo [dstalk] Conan 依赖已就绪
+)
+
+:: ============================================================
+:: 6. CMake 配置 + Ninja 编译
+:: ============================================================
+echo [dstalk] CMake 配置 + 编译...
+"%TOOLS%cmake\bin\cmake.exe" -S "%ROOT%" -B "%ROOT%build" -G Ninja ^
+  -DCMAKE_C_COMPILER="%TOOLS%llvm\bin\clang.exe" ^
+  -DCMAKE_CXX_COMPILER="%TOOLS%llvm\bin\clang++.exe" ^
+  -DCMAKE_TOOLCHAIN_FILE="%ROOT%build\conan_toolchain.cmake" ^
+  -DCMAKE_BUILD_TYPE=Release
+if !errorlevel! neq 0 (
+    echo   [ERROR] CMake 配置失败
+    pause & exit /b 1
+)
+
+"%TOOLS%cmake\bin\cmake.exe" --build "%ROOT%build"
+if !errorlevel! neq 0 (
+    echo   [ERROR] 编译失败
+    pause & exit /b 1
+)
+
+echo.
+echo ============================================
+echo   编译成功!
+echo   build\dstalk-core\dstalk.dll
+echo   build\dstalk-cli\dstalk-cli.exe
+echo   build\dstalk-gui\dstalk-gui.exe
+echo ============================================
+pause