[core] Fix clean build files to properly clear PlatformIO cache

esphome/core/__init__.py

@@ -694,6 +694,15 @@ class EsphomeCore:
     def relative_piolibdeps_path(self, *path):
         return self.relative_build_path(".piolibdeps", *path)
 
+    @property
+    def platformio_cache_dir(self) -> str:
+        """Get the PlatformIO cache directory path."""
+        # Check if running in Docker/HA addon with custom cache dir
+        if cache_dir := os.environ.get("PLATFORMIO_CACHE_DIR"):
+            return cache_dir
+        # Default PlatformIO cache location
+        return os.path.expanduser("~/.platformio/.cache")
+
     @property
     def firmware_bin(self):
         if self.is_libretiny:

esphome/writer.py

@@ -315,6 +315,13 @@ def clean_build():
         _LOGGER.info("Deleting %s", dependencies_lock)
         os.remove(dependencies_lock)
 
+    # Clean PlatformIO cache to resolve CMake compiler detection issues
+    # This helps when toolchain paths change or get corrupted
+    cache_dir = CORE.platformio_cache_dir
+    if os.path.isdir(cache_dir):
+        _LOGGER.info("Deleting PlatformIO cache %s", cache_dir)
+        shutil.rmtree(cache_dir)
+
 
 GITIGNORE_CONTENT = """# Gitignore settings for ESPHome
 # This is an example and may include too much for your use-case.