address review: fix sdist detection, code-block lang, add PoC disclaimers

Author: mlukasze

docs/articles_en/get-started/install-openvino/configurations/troubleshooting-install-config.rst

@@ -38,6 +38,11 @@ Troubleshooting Guide for OpenVINO™ Installation & Configuration
 
 .. dropdown:: ``pip install --no-binary openvino openvino`` fails
 
+   .. note::
+
+      Source distribution (sdist) installation is experimental. For most users, the
+      recommended path is ``pip install openvino`` (prebuilt wheel).
+
    Installation from source distribution requires local build tools and Python build dependencies.
    Before retrying installation, update your packaging tools:
 

docs/articles_en/get-started/install-openvino/install-openvino-pip.rst

@@ -92,14 +92,16 @@ Use the following command to install either the base or GenAI OpenVINO package:
 
 If you want to install from source distribution (sdist), use the following command:
 
-.. code-block:: python
+.. code-block:: sh
 
    python -m pip install --no-binary openvino openvino
 
 .. note::
 
-   Installing from source distribution requires build tools and may take more time
-   than wheel-based installation.
+   Installing from source distribution is experimental (PoC) and requires a full
+   native build toolchain (C/C++ compiler, CMake, Python headers). It may take
+   significantly more time than wheel-based installation. For most users, the
+   prebuilt wheel installation shown above is the recommended option.
 
 Step 5. Verify that the Package Is Installed
 ++++++++++++++++++++++++++++++++++++++++++++

setup.py

@@ -49,7 +49,9 @@
 OPENVINO_SOURCE_DIR = os.getenv("OPENVINO_SOURCE_DIR", SCRIPT_DIR)
 OPENVINO_BINARY_DIR = os.getenv("OPENVINO_BINARY_DIR", f'{OPENVINO_SOURCE_DIR}/build_wheel')
 OPENVINO_PYTHON_BINARY_DIR = os.getenv("OPENVINO_PYTHON_BINARY_DIR", "python_build")
-SDIST_BUILD = "sdist" in sys.argv
+# Detect sdist context: either we are running `setup.py sdist` to create the archive,
+# or we are building from an unpacked sdist (PKG-INFO is generated by sdist)
+SDIST_BUILD = "sdist" in sys.argv or (SCRIPT_DIR / "PKG-INFO").is_file()
 CONFIG = os.getenv("BUILD_TYPE", "Release")
 OV_RUNTIME_LIBS_DIR = os.getenv("OV_RUNTIME_LIBS_DIR", f"runtime/{LIBS_DIR}/{ARCH}")
 TBB_LIBS_DIR = os.getenv("TBB_LIBS_DIR", f"runtime/3rdparty/tbb/{LIBS_DIR}")