feat: rename process module to os and add Platform class with name and isPosix methods

Rename the "process" module to "os" across all source files, documentation, tests, and build configuration. Add a new Platform class to the os module with static methods `name` (returns OS string like "Windows", "Linux", "OS X", "iOS", "Unix", "POSIX", or "Unknown") and `isPosix` (returns bool indicating POSIX compliance). Update all import paths from "process" to "os" in test files and module registrations. Move process.c/h to os.c/h, rename processSetArguments to osSetArguments, and regenerate the os.wren.inc bytecode source. Add documentation pages for the os module and Platform class.

src/cli/main.c

@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "process.h"
+#include "os.h"
 #include "vm.h"
 #include "wren.h"
 
@@ -14,7 +14,7 @@ int main(int argc, const char* argv[])
     return 0;
   }
   
-  processSetArguments(argc, argv);
+  osSetArguments(argc, argv);
 
   if (argc == 1)
   {

src/cli/modules.c

@@ -4,7 +4,7 @@
 #include "modules.h"
 
 #include "io.wren.inc"
-#include "process.wren.inc"
+#include "os.wren.inc"
 #include "scheduler.wren.inc"
 #include "timer.wren.inc"
 
@@ -21,6 +21,8 @@ extern void fileRealPath(WrenVM* vm);
 extern void fileSize(WrenVM* vm);
 extern void fileStat(WrenVM* vm);
 extern void fileWriteBytes(WrenVM* vm);
+extern void platformIsPosix(WrenVM* vm);
+extern void platformName(WrenVM* vm);
 extern void processAllArguments(WrenVM* vm);
 extern void statPath(WrenVM* vm);
 extern void statBlockCount(WrenVM* vm);
@@ -149,7 +151,11 @@ static ModuleRegistry modules[] =
       STATIC_METHOD("readStop_()", stdinReadStop)
     END_CLASS
   END_MODULE
-  MODULE(process)
+  MODULE(os)
+    CLASS(Platform)
+      STATIC_METHOD("isPosix", platformIsPosix)
+      STATIC_METHOD("name", platformName)
+    END_CLASS
     CLASS(Process)
       STATIC_METHOD("allArguments", processAllArguments)
     END_CLASS