fix: add type annotation for Vec<String> to fix Windows build (#452)

The compiler cannot infer the element type of `conflicts` on Windows
because all `push` calls are inside `#[cfg(unix)]` blocks which don't
compile on Windows.

Co-authored-by: Claude Sonnet 4.6 (1M context) <[email protected]>

src/setup/channels.rs

@@ -566,7 +566,7 @@ async fn setup_tunnel_cloudflare() -> Result<TunnelSettings, ChannelSetupError>
 /// Detect running cloudflared processes or managed services that could conflict
 /// with IronClaw's tunnel management.
 fn detect_existing_cloudflared() -> Option<String> {
-    let mut conflicts = Vec::new();
+    let mut conflicts: Vec<String> = Vec::new();
 
     // Check for running cloudflared processes (all platforms)
     #[cfg(unix)]