build: fix libghostty shared lib install for Windows

On Windows, install as ghostty.dll + ghostty-static.lib instead of
libghostty.so + libghostty.a, following Windows naming conventions.
Guard ubsan_rt bundling in initStatic for MSVC compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/build/GhosttyLib.zig

@@ -39,6 +39,12 @@ pub fn initStatic(
     lib.bundle_compiler_rt = true;
     lib.bundle_ubsan_rt = true;
 
+    if (deps.config.target.result.os.tag == .windows) {
+        // Zig's ubsan emits /exclude-symbols linker directives that
+        // are incompatible with the MSVC linker (LNK4229).
+        lib.bundle_ubsan_rt = false;
+    }
+
     // Add our dependencies. Get the list of all static deps so we can
     // build a combined archive if necessary.
     var lib_list = try deps.add(lib);