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/console/piterminal.cpp

@@ -21,7 +21,9 @@
 #include "piincludes_p.h"
 #include "piliterals_time.h"
 #include "pisharedmemory.h"
-#ifndef MICRO_PIP
+
+#if !defined(PICO_SDK)
+#ifndef PIP_NO_PROCESS
 #  ifdef WINDOWS
 #	include <windows.h>
 #	include <wingdi.h>
@@ -346,8 +348,8 @@ void PITerminal::getCursor(int & x, int & y) {
 	int sz = 0;
 	PRIVATE->shm->read(&sz, 4);
 #  else
-	x = PRIVATE->cur_x;
-	y = PRIVATE->cur_y;
+	x                   = PRIVATE->cur_x;
+	y                   = PRIVATE->cur_y;
 #  endif
 }
 
@@ -934,7 +936,7 @@ void PITerminal::destroy() {
 	}
 	if (PRIVATE->pipe != INVALID_HANDLE_VALUE) CloseHandle(PRIVATE->pipe);
 	if (PRIVATE->hConBuf != INVALID_HANDLE_VALUE) CloseHandle(PRIVATE->hConBuf);
-	// piCout << "destroy" << size_y;
+		// piCout << "destroy" << size_y;
 #  else
 #	ifdef HAS_FORKPTY
 	if (PRIVATE->pid != 0) kill(PRIVATE->pid, SIGKILL);
@@ -977,4 +979,6 @@ bool PITerminal::resize(int cols, int rows) {
 	return ret;
 }
 
-#endif // MICRO_PIP
+#endif // PIP_NO_PROCESS
+
+#endif // !PICO_SDK