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/io_devices/piiodevice.h

@@ -59,26 +59,20 @@ typedef std::function<bool(const uchar *, int, void *)> ReadRetFunc;
 
 #else
 
-#  define REGISTER_DEVICE(name)                                                                                    \
-	  STATIC_INITIALIZER_BEGIN                                                                                     \
-		  PIIODevice::registerDevice(name::fullPathPrefixS(), #name, []() -> PIIODevice * { return new name(); }); \
-	  STATIC_INITIALIZER_END
+#  define REGISTER_DEVICE(name)                                                                                \
+	STATIC_INITIALIZER_BEGIN                                                                                   \
+	  PIIODevice::registerDevice(name::fullPathPrefixS(), #name, []() -> PIIODevice * { return new name(); }); \
+	STATIC_INITIALIZER_END
 
-#  define PIIODEVICE(name, prefix)                   \
-	  PIOBJECT_SUBCLASS(name, PIIODevice)            \
-	  PIIODevice * copy() const override {           \
-		  return new name();                         \
-	  }                                              \
-                                                     \
-  public:                                            \
-	  PIConstChars fullPathPrefix() const override { \
-		  return prefix;                             \
-	  }                                              \
-	  static PIConstChars fullPathPrefixS() {        \
-		  return prefix;                             \
-	  }                                              \
-                                                     \
-  private:
+#  define PIIODEVICE(name, prefix)                                  \
+	PIOBJECT_SUBCLASS(name, PIIODevice)                             \
+	PIIODevice * copy() const override { return new name(); }       \
+                                                                    \
+public:                                                             \
+	PIConstChars fullPathPrefix() const override { return prefix; } \
+	static PIConstChars fullPathPrefixS() { return prefix; }        \
+                                                                    \
+private:
 
 
 #endif
@@ -248,7 +242,7 @@ public:
 	//! \~russian Возвращает пользовательские данные, передаваемые в callback потокового чтения.
 	void * threadedReadData() const { return ret_data_; }
 
-
+#ifndef PIP_NO_THREADS
 	//! \~english Returns whether threaded read is running.
 	//! \~russian Возвращает, запущено ли потоковое чтение.
 	bool isThreadedRead() const;
@@ -279,6 +273,7 @@ public:
 	//! \~english Waits until threaded read finishes or "timeout" expires.
 	//! \~russian Ожидает завершения потокового чтения, но не дольше "timeout".
 	bool waitThreadedReadFinished(PISystemTime timeout = {});
+#endif // PIP_NO_THREADS
 
 
 	//! \~english Returns delay between unsuccessful threaded read attempts in milliseconds.
@@ -367,6 +362,7 @@ public:
 	PIByteArray readForTime(PISystemTime timeout);
 
 
+#ifndef PIP_NO_THREADS
 	//! \~english Queues "data" for threaded write and returns task ID.
 	//! \~russian Помещает "data" в очередь потоковой записи и возвращает ID задания.
 	ullong writeThreaded(const void * data, ssize_t max_size) { return writeThreaded(PIByteArray(data, uint(max_size))); }
@@ -374,6 +370,7 @@ public:
 	//! \~english Queues byte array "data" for threaded write and returns task ID.
 	//! \~russian Помещает массив байт "data" в очередь потоковой записи и возвращает ID задания.
 	ullong writeThreaded(const PIByteArray & data);
+#endif
 
 
 	//! \~english Configures the device from section "section" of file "config_file".
@@ -611,16 +608,18 @@ private:
 	static PIMap<PIConstChars, FabricInfo> & fabrics();
 
 	PITimeMeasurer tm, reopen_tm;
-	PIThread read_thread, write_thread;
 	PIByteArray buffer_in, buffer_tr;
-	PIQueue<PIPair<PIByteArray, ullong>> write_queue;
 	PISystemTime reopen_timeout;
 	ullong tri = 0;
 	uint threaded_read_buffer_size, threaded_read_timeout_ms = 10;
 	bool reopen_enabled = true, destroying = false;
-
-	static PIMutex nfp_mutex;
 	static PIMap<PIString, PIString> nfp_cache;
+
+#ifndef PIP_NO_THREADS
+	PIThread read_thread, write_thread;
+	PIQueue<PIPair<PIByteArray, ullong>> write_queue;
+	static PIMutex nfp_mutex;
+#endif
 };
 
 #endif // PIIODEVICE_H