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/thread/pithreadpoolworker.h

@@ -6,7 +6,7 @@
 /*
     PIP - Platform Independent Primitives
 
-	Ivan Pelipenko, Stephan Fomenko
+    Ivan Pelipenko, Stephan Fomenko
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Lesser General Public License as published by
@@ -33,6 +33,7 @@
 //! \~\brief
 //! \~english Fixed-size pool of worker threads for generic-purpose tasks.
 //! \~russian Фиксированный пул рабочих потоков для задач общего назначения.
+#ifndef PIP_NO_THREADS
 class PIP_EXPORT PIThreadPoolWorker: public PIObject {
 	PIOBJECT(PIThreadPoolWorker)
 
@@ -109,7 +110,7 @@ public:
 	template<typename O>
 	int64_t enqueueTask(O * obj, void (O::*member_func)(int64_t)) {
 		return enqueueTask([obj, member_func](int64_t id) { (obj->*member_func)(id); },
-						   PIObject::isPIObject(obj) ? dynamic_cast<PIObject *>(obj) : nullptr);
+		                   PIObject::isPIObject(obj) ? dynamic_cast<PIObject *>(obj) : nullptr);
 	}
 
 	//! \~english Queue class member method to execution. Returns task ID.
@@ -117,7 +118,7 @@ public:
 	template<typename O>
 	int64_t enqueueTask(O * obj, void (O::*member_func)()) {
 		return enqueueTask([obj, member_func](int64_t) { (obj->*member_func)(); },
-						   PIObject::isPIObject(obj) ? dynamic_cast<PIObject *>(obj) : nullptr);
+		                   PIObject::isPIObject(obj) ? dynamic_cast<PIObject *>(obj) : nullptr);
 	}
 
 	//! \~english Remove task with id \a id from queue. Returns if task delete.
@@ -172,6 +173,7 @@ private:
 	PISet<PIObject *> contexts;
 	std::atomic_int64_t next_task_id = {0};
 };
+#endif // PIP_NO_THREADS
 
 
 #endif // PITHREADPOOLWORKER_H