fix(windows): link memset_shim object directly and suppress dead_code warning

- Use rustc-link-arg to directly link memset_shim.o object file
  instead of -l flag, ensuring symbol is available regardless of
  link order with libsodium_sys

- Add #[allow(dead_code)] to find_ollama_binary() which is only
  used inside cfg(target_os = "macos") and cfg(target_os = "linux")
  blocks, causing false positive warning when cross-compiling for Windows

src-tauri/build.rs

@@ -9,18 +9,18 @@ fn main() {
     // libsodium-sys-stable uses memset_explicit which isn't available in MinGW
     let target_os = std::env::var("CARGO_CFG_TARGET_OS").unwrap_or_default();
     let target_env = std::env::var("CARGO_CFG_TARGET_ENV").unwrap_or_default();
-
+    
     if target_os == "windows" && target_env == "gnu" {
         let out_dir = std::env::var("OUT_DIR").unwrap();
         let obj_path = format!("{}/memset_shim.o", out_dir);
-
+        
         cc::Build::new()
             .file("memset_s_shim.c")
             .define("WIN32", None)
             .define("__WIN32__", None)
             .out_dir(&out_dir)
             .compile("memset_shim");
-
+        
         println!("cargo:rerun-if-changed=memset_s_shim.c");
         // Directly link the object file instead of using -l flag
         // This ensures the symbol is available regardless of link order