Add assetfix, transmogfix, minimapicons modules; fix assetfix disk-vs-MPQ priority

Assetfix: hook CheckFileExistence to serve loose Data\ files. The original
flags|1 approach failed because game paths contain backslashes, causing
CheckFileExistence to skip BuildFilePath and check the raw path (no Data\
prefix). Fix: write the correct Data\-prefixed disk path to the output buffer
directly and return 1, bypassing the original function for hash map hits.
This preserves hook chaining (filename argument is never transformed).

Also adds transmogfix (transmog update coalescing), minimapicons (stub),
new build options for all three modules, mutex-based multi-DLL safety,
embed .skin data into .m2 models, and various module improvements.

src/combatlog/combatlog.zig

@@ -5,10 +5,48 @@
 //!
 //! TODO: Find and hook the combat log open/create function.
 
+const std = @import("std");
 const con = @import("../console.zig");
 
+const WINAPI = std.builtin.CallingConvention.winapi;
+extern "kernel32" fn CreateMutexA(lpMutexAttributes: ?*anyopaque, bInitialOwner: i32, lpName: [*:0]const u8) callconv(WINAPI) ?*anyopaque;
+extern "kernel32" fn ReleaseMutex(hMutex: *anyopaque) callconv(WINAPI) i32;
+extern "kernel32" fn CloseHandle(hObject: *anyopaque) callconv(WINAPI) i32;
+extern "kernel32" fn GetLastError() callconv(WINAPI) u32;
+extern "kernel32" fn GetCurrentProcessId() callconv(WINAPI) u32;
+const ERROR_ALREADY_EXISTS: u32 = 183;
+
+var g_mutex: ?*anyopaque = null;
+var g_is_hook_owner: bool = false;
+
 pub fn installHooks() void {
     con.print("[combatlog] Module loaded (stub)\n");
+
+    // Multi-DLL safety: only one instance per process should hook
+    var mutex_name_buf: [64]u8 = undefined;
+    const mutex_name = std.fmt.bufPrint(&mutex_name_buf, "Local\\CombatlogHook_{d}", .{GetCurrentProcessId()}) catch return;
+    mutex_name_buf[mutex_name.len] = 0;
+
+    g_mutex = CreateMutexA(null, 1, @ptrCast(mutex_name_buf[0..mutex_name.len :0]));
+    if (g_mutex == null) return;
+
+    if (GetLastError() == ERROR_ALREADY_EXISTS) {
+        _ = CloseHandle(g_mutex.?);
+        g_mutex = null;
+        g_is_hook_owner = false;
+        con.print("[combatlog] Another DLL owns hooks (mutex taken), skipping\n");
+        return;
+    }
+    g_is_hook_owner = true;
 }
 
-pub fn removeHooks() void {}
+pub fn removeHooks() void {
+    if (g_is_hook_owner) {
+        if (g_mutex) |m| {
+            _ = ReleaseMutex(m);
+            _ = CloseHandle(m);
+            g_mutex = null;
+        }
+    }
+    g_is_hook_owner = false;
+}