Desktop shell: one exit path, one startup surface and a real tray probe

desktop/src-tauri/Cargo.toml

@@ -29,6 +29,12 @@ tauri-plugin-single-instance = "=2.4.0"
 tauri-plugin-updater = "=2.9.0"
 tokio = { version = "=1.45.1", features = ["sync", "time"] }
 
+# Linux only, and already in this graph: `tao` enables its own `dbus` feature by default, so
+# `libdbus-sys` is compiled for every Linux build of this shell today. Naming it here adds a
+# session-bus probe for the StatusNotifier watcher without adding a package or a system library.
+[target.'cfg(target_os = "linux")'.dependencies]
+dbus = "=0.9.12"
+
 [profile.release]
 codegen-units = 1
 lto = "thin"

desktop/src-tauri/src/endpoint.rs

@@ -0,0 +1,33 @@
+//! The loopback endpoint the shell talks to.
+//!
+//! This file was `discovery.rs`, and it resolved the endpoint itself: it read `runtime-port.json`,
+//! fell back to 10100 and let the shell start there, so a user with a configured `config.port` was
+//! started on a port they had not chosen. Resolution belongs to the bundled CLI now — see
+//! `resolve.rs` — and what is left here is the value it hands back.
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ProxyEndpoint {
+    pub host: &'static str,
+    pub port: u16,
+}
+
+impl ProxyEndpoint {
+    pub fn url(&self, path: &str) -> String {
+        format!("http://{}:{}{}", self.host, self.port, path)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ProxyEndpoint;
+
+    #[test]
+    fn the_endpoint_is_loopback_and_carries_its_port() {
+        let endpoint = ProxyEndpoint {
+            host: "127.0.0.1",
+            port: 12345,
+        };
+        assert_eq!(endpoint.url("/healthz"), "http://127.0.0.1:12345/healthz");
+        assert_eq!(endpoint.url(""), "http://127.0.0.1:12345");
+    }
+}