feat(client): modern CLI output + Windows exe icon

- Replace timestamp-based log macros with colored CLI output system
  using the `colored` crate
- Banner on startup: ☀ HELIOS REMOTE + separator line
- Colored prefixes: cyan → (status), green ✓ (ok), red ✗ (error),
  yellow ⚡ (incoming commands)
- Session info on connect: ✓ Connected · <label> · Session <id>
- No timestamps, no [CMD]/[OK]/[ERR] prefixes
- Suppress tracing output by default (RUST_LOG=off unless set)
- Add build.rs to embed logo.ico as Windows resource via winres
- Add winres as build-dependency in client Cargo.toml

crates/client/build.rs

@@ -0,0 +1,8 @@
+fn main() {
+    #[cfg(target_os = "windows")]
+    {
+        let mut res = winres::WindowsResource::new();
+        res.set_icon("../../assets/logo.ico");
+        res.compile().expect("Failed to compile Windows resources");
+    }
+}