fix(win): add Windows branch to pb_rss_kb + link psapi

CI Windows builds failed in printable_binary.c with:
  error: call to undeclared function 'sysconf'
  error: use of undeclared identifier '_SC_PAGESIZE'

Fix: extend the pb_rss_kb() RSS-reporting helper with a Windows branch
using GetProcessMemoryInfo from psapi.h (parallel to the existing
__APPLE__ branch using mach_task_basic_info). Make <unistd.h> include
non-Windows-only and add windows.h / psapi.h on Windows.

Also: pass -lpsapi to 'zig cc' so GetProcessMemoryInfo links cleanly
in the Windows job.

Author: pmarreck

.github/workflows/ci.yml

@@ -154,7 +154,7 @@ jobs:
       - name: Build C via zig cc
         shell: bash
         run: |
-          zig cc -O3 -I. -o printable-binary-c.exe src/printable_binary.c
+          zig cc -O3 -I. -o printable-binary-c.exe src/printable_binary.c -lpsapi
 
       - name: Run Zig unit tests
         run: zig build test

src/printable_binary.c

@@ -10,7 +10,12 @@
 #include <string.h>
 #include <stdint.h>
 #include <stdbool.h>
+#if defined(_WIN32)
+#include <windows.h>
+#include <psapi.h>
+#else
 #include <unistd.h>
+#endif
 #include <time.h>
 #if defined(__APPLE__)
 #include <mach/mach.h>
@@ -1633,6 +1638,10 @@ static long pb_rss_kb(void) {
     mach_msg_type_number_t count = MACH_TASK_BASIC_INFO_COUNT;
     if (task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&info, &count) != KERN_SUCCESS) return -1;
     return (long)(info.resident_size / 1024);
+#elif defined(_WIN32)
+    PROCESS_MEMORY_COUNTERS pmc;
+    if (!GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc))) return -1;
+    return (long)(pmc.WorkingSetSize / 1024);
 #else
     FILE *f = fopen("/proc/self/statm", "r");
     if (!f) return -1;