Fix ESP-IDF CI build

[gmartin82]

Description

Fix PlatformIO source filtering so platform-specific backend files are selected consistently with the CMake platform profiles.

PlatformIO was auto-discovering sources outside src/system/**, including platform-specific transport backends under src/link/transport/**. This meant builds could include sources for the wrong platform, for example ESP-IDF builds attempting to compile Arduino ESP32 C++ transport files.

What does this PR do?

This PR updates extra_script.py to:

• exclude platform-specific system and transport backend directories from PlatformIO’s default source discovery;
• read the selected CMake platform profile from cmake/platforms/<platform>.cmake;
• derive PlatformIO source-filter add-backs from the ZP_PLATFORM_SOURCE_FILES listed by that CMake profile;
• keep the CMake platform files as the source of truth for platform-specific source composition.

Why is this change needed?

The previous PlatformIO filter treated src/system/** as the platform-specific boundary, but the platform-composition rework also has platform-specific files under src/link/transport/**, such as Arduino ESP32 Bluetooth and serial sources.

Because PlatformIO starts from +<*>, those files could be picked up even when the active platform profile did not select them. This caused incorrect cross-platform compilation, for example ESP-IDF builds trying to compile Arduino-specific C++ files.

Deriving the PlatformIO filter from the CMake platform profile avoids duplicating the source list in extra_script.py and keeps PlatformIO aligned with the existing CMake platform selection.

Related Issues

Related to PlatformIO build failures where ESP-IDF attempted to compile Arduino ESP32 transport sources.

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