feat: add compile_options support to idf.py build-file

Allow specifying extra compiler flags (warning flags, preprocessor
definitions, etc.) via a new 'compile_options' entry in the
idf-build-file frontmatter. The options are applied to the source
file via target_compile_options in the generated main component
CMakeLists, with CMake quoting so that flags like -DMSG="hello world"
reach the compiler exactly as written.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/zh_CN/api-guides/tools/idf-build-file.rst

@@ -67,6 +67,17 @@
       - CONFIG_IDF_TARGET=esp32s3
       - CONFIG_SPIRAM=y
 
+``compile_options``
+^^^^^^^^^^^^^^^^^^^
+
+编译源文件时使用的额外编译器选项列表，例如警告标志或预处理器定义。
+
+.. code-block:: yaml
+
+    compile_options:
+      - -Wconversion
+      - -DBUFFER_SIZE=1024
+
 ``dependencies``
 ^^^^^^^^^^^^^^^^