fix: build errors in ostp-guard, ostp-daemon, ostp-installer

- Make check_analysis_tools() public in ostp-guard
- Fix PWSTR type in ostp-installer (use windows::core::PWSTR)
- Remove unused imports (Context, Foundation, fileapi, minwindef)

Build artifacts in dist/:
- Linux x64: ostp-server (9.2 MB), oncp-master (4.8 MB)
- Windows x64: ostp-client.exe (1.64 MB), ostp-daemon.exe (0.53 MB), ostp-installer.exe (0.37 MB)

ostp-installer/src/main.rs

@@ -8,7 +8,7 @@
 
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
-use anyhow::{Context, Result};
+use anyhow::Result;
 use std::path::PathBuf;
 
 mod wizard;

ostp-installer/src/service.rs

@@ -55,7 +55,7 @@ pub fn install_service() -> Result<()> {
         // Set description
         let description_wide = to_wide_string(description);
         let mut service_desc = SERVICE_DESCRIPTIONW {
-            lpDescription: PWSTR(description_wide.as_ptr() as *mut _),
+            lpDescription: windows::core::PWSTR(description_wide.as_ptr() as *mut _),
         };
 
         ChangeServiceConfig2W(