refactor: migrate MICRO_PIP to fine-grained feature flags

Replace monolithic MICRO_PIP/PIP_MICRO with granular flags:

Feature flags (CMake options + platform auto-detection):
- PIP_NO_FILESYSTEM, PIP_NO_THREADS, PIP_NO_SOCKET
- PIP_NO_PROCESS, PIP_NO_DYNLIB, PIP_NO_FFT, PIP_NO_SERIAL

Embedded optimization flag:
- PIP_EMBEDDED (auto-set for Pico SDK and FreeRTOS)
  Controls buffer sizes, time stubs, terminal fallback, init stubs

Platform blocks in CMakeLists.txt:
- Pico SDK: auto-disables FS, PROCESS, DYNLIB, FFT, SERIAL;
  conditionally disables THREADS (no FreeRTOS) and SOCKET (no LWIP)
- FreeRTOS: auto-disables FS, PROCESS, DYNLIB, FFT, SERIAL;
  conditionally disables SOCKET (no LWIP)
- Android: auto-disables PROCESS, DYNLIB, FFT

Updated 96 files across libs/, utils/, tests/, and CMakeLists.txt.
Builds verified for Linux (547 tests pass) and Pico SDK (100%).
Removed all MICRO_PIP and PIP_MICRO references (0 remaining).

libs/main/system/pihidevice.h

@@ -169,6 +169,7 @@ PIP_EXPORT PICout operator<<(PICout s, const PIHIDeviceInfo & v);
 //! \~english Provides access to HID (Human Interface Device) devices such as game controllers, joysticks, and other input devices.
 //! \~russian Предоставляет доступ к HID (Human Interface Device) устройствам, таким как геймконтроллеры, джойстики и другие устройства
 //! ввода.
+#ifndef PIP_NO_THREADS
 class PIP_EXPORT PIHIDevice: public PIThread {
 	PIOBJECT_SUBCLASS(PIHIDevice, PIThread)
 
@@ -188,7 +189,7 @@ public:
 			tNone /** \~english Empty event \~russian Пустое событие */,
 			tButton /** \~english Button state change \~russian Изменение состояния кнопки */,
 			tAxisMove /** \~english Axis value change or relative axis delta \~russian Изменение значения оси или дельта относительной оси
-					   */
+			           */
 				,
 		};
 
@@ -270,6 +271,7 @@ private:
 	PIMap<int, int> prev_buttons, cur_buttons;
 	float dead_zone = 0.f;
 };
+#endif // PIP_NO_THREADS
 
 
 #endif