refactor: rename PIP_NO_\* to PIP_HAS_\* with inverted logic

All feature flags now use positive naming (enabled by default):
- PIP_HAS_FILESYSTEM, PIP_HAS_THREADS, PIP_HAS_SOCKET
- PIP_HAS_PROCESS, PIP_HAS_DYNLIB, PIP_HAS_FFT, PIP_HAS_SERIAL

Preprocessor guards inverted:
- #ifndef PIP_NO_X → #ifdef PIP_HAS_X
- #ifdef PIP_NO_X → #ifndef PIP_HAS_X

CMake options default ON instead of OFF.
Platform blocks set flags OFF to disable features.

85 files transformed via Python script + 2 manual fixes.

libs/main/io_devices/pibinarylog.cpp

@@ -24,7 +24,7 @@
 #include "piliterals_time.h"
 #include "pipropertystorage.h"
 
-#ifndef PIP_NO_FILESYSTEM
+#ifdef PIP_HAS_FILESYSTEM
 #  include "pitime.h"
 #  include "pitranslator.h"
 
@@ -60,11 +60,11 @@ static const uchar binlog_sig[] = {'B', 'I', 'N', 'L', 'O', 'G'};
 REGISTER_DEVICE(PIBinaryLog)
 
 PIBinaryLog::PIBinaryLog() {
-#  ifdef PIP_NO_THREADS
+#  ifndef PIP_HAS_THREADS
 	setThreadedReadBufferSize(512);
 #  else
 	setThreadedReadBufferSize(64_KiB);
-#  endif // PIP_NO_THREADS
+#  endif // PIP_HAS_THREADS
 	is_started = is_indexed = is_pause = false;
 	create_index_on_fly                = false;
 	current_index                      = -1;
@@ -1011,4 +1011,4 @@ void PIBinaryLog::CompleteIndex::makeIndexPos() {
 		index_pos[index[i].pos] = i;
 }
 
-#endif // PIP_NO_FILESYSTEM
+#endif // PIP_HAS_FILESYSTEM