Theme (macOS): moves macOS theme detection logic from DE to dedicated module

The old behavior was inherited from neofetch. However `Aqua` and `Liquid Glass` are actually design language, not a DE. There is no DE on macOS.

CMakeLists.txt

@@ -974,7 +974,7 @@ elseif(APPLE)
         src/detection/terminalfont/terminalfont_apple.m
         src/detection/terminalshell/terminalshell_linux.c
         src/detection/terminalsize/terminalsize_linux.c
-        src/detection/theme/theme_nosupport.c
+        src/detection/theme/theme_apple.c
         src/detection/tpm/tpm_apple.c
         src/detection/uptime/uptime_bsd.c
         src/detection/users/users_linux.c

src/detection/displayserver/displayserver_apple.c

@@ -196,21 +196,5 @@ void ffConnectDisplayServerImpl(FFDisplayServerResult* ds)
         }
     }
 
-    const FFOSResult* os = ffDetectOS();
-
-    char* str_end;
-    const char* version = os->version.chars;
-    unsigned long osNum = strtoul(version, &str_end, 10);
-    if (str_end != version)
-    {
-        if (osNum > 15) { // Tahoe
-            ffStrbufSetStatic(&ds->dePrettyName, "Liquid Glass");
-        } else if (osNum < 10) {
-            ffStrbufSetStatic(&ds->dePrettyName, "Platinum");
-        } else {
-            ffStrbufSetStatic(&ds->dePrettyName, "Aqua");
-        }
-    }
-
     detectDisplays(ds);
 }

src/detection/theme/theme_apple.c

@@ -0,0 +1,24 @@
+#include "theme.h"
+
+#include "detection/os/os.h"
+
+const char* ffDetectTheme(FFThemeResult* result)
+{
+    const FFOSResult* os = ffDetectOS();
+
+    char* str_end;
+    const char* version = os->version.chars;
+    unsigned long osNum = strtoul(version, &str_end, 10);
+    if (str_end != version)
+    {
+        if (osNum > 15) { // Tahoe
+            ffStrbufSetStatic(&result->theme1, "Liquid Glass");
+        } else if (osNum < 10) {
+            ffStrbufSetStatic(&result->theme1, "Platinum");
+        } else {
+            ffStrbufSetStatic(&result->theme1, "Aqua");
+        }
+    }
+
+    return NULL;
+}