Fix Windows crate 0.58 API compatibility

- Define XBUTTON1/XBUTTON2 constants (removed from windows crate)
- Update D3D11_CPU_ACCESS_FLAG usage
- Fix CreateTexture2D output parameter
- Fix BitBlt/EnumDisplayMonitors return type handling
- Fix encode_utf16 iterator usage

agent/src/capture/gdi.rs

@@ -4,7 +4,7 @@
 //! Slower than DXGI but works on older systems and edge cases.
 
 use super::{CapturedFrame, Capturer, Display};
-use anyhow::{Context, Result};
+use anyhow::Result;
 use std::time::Instant;
 
 use windows::Win32::Graphics::Gdi::{
@@ -58,7 +58,7 @@ impl GdiCapturer {
             let old_bitmap = SelectObject(mem_dc, bitmap);
 
             // Copy screen to memory DC
-            let result = BitBlt(
+            if let Err(e) = BitBlt(
                 mem_dc,
                 0,
                 0,
@@ -68,14 +68,12 @@ impl GdiCapturer {
                 self.display.x,
                 self.display.y,
                 SRCCOPY,
-            );
-
-            if !result.as_bool() {
+            ) {
                 SelectObject(mem_dc, old_bitmap);
                 DeleteObject(bitmap);
                 DeleteDC(mem_dc);
                 ReleaseDC(HWND::default(), screen_dc);
-                anyhow::bail!("BitBlt failed");
+                anyhow::bail!("BitBlt failed: {}", e);
             }
 
             // Prepare bitmap info for GetDIBits