feat: add websocket browser service runtime

Wire the service/browser runtime onto the websocket-driven execution path and add the new browser/service modules needed for the submit flow and runtime integration.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/bin/sg_claw_client.rs

@@ -0,0 +1,78 @@
+use std::io::{self, BufRead};
+
+use sgclaw::service::{ClientMessage, ServiceMessage};
+use tungstenite::{connect, Message};
+
+fn main() -> std::process::ExitCode {
+    match run() {
+        Ok(()) => std::process::ExitCode::SUCCESS,
+        Err(err) => {
+            eprintln!("sg_claw_client failed: {err}");
+            std::process::ExitCode::FAILURE
+        }
+    }
+}
+
+fn parse_request(input: &str) -> (ClientMessage, bool) {
+    match input.trim() {
+        "/connect" => (ClientMessage::Connect, true),
+        "/start" => (ClientMessage::Start, true),
+        "/stop" => (ClientMessage::Stop, true),
+        instruction => (
+            ClientMessage::SubmitTask {
+                instruction: instruction.to_string(),
+                conversation_id: String::new(),
+                messages: vec![],
+                page_url: String::new(),
+                page_title: String::new(),
+            },
+            false,
+        ),
+    }
+}
+
+fn run() -> Result<(), String> {
+    let service_url = std::env::var("SG_CLAW_SERVICE_WS_URL")
+        .unwrap_or_else(|_| "ws://127.0.0.1:42321".to_string());
+    let (mut socket, _) = connect(service_url.as_str()).map_err(|err| err.to_string())?;
+
+    let mut input = String::new();
+    io::stdin()
+        .lock()
+        .read_line(&mut input)
+        .map_err(|err| err.to_string())?;
+
+    let (request, exit_on_status) = parse_request(&input);
+
+    let payload = serde_json::to_string(&request).map_err(|err| err.to_string())?;
+    socket
+        .send(Message::Text(payload.into()))
+        .map_err(|err| err.to_string())?;
+
+    loop {
+        match socket.read().map_err(|err| err.to_string())? {
+            Message::Text(text) => {
+                let message: ServiceMessage =
+                    serde_json::from_str(&text).map_err(|err| err.to_string())?;
+                match message {
+                    ServiceMessage::StatusChanged { state } => {
+                        println!("status: {state}");
+                        if exit_on_status {
+                            return Ok(());
+                        }
+                    }
+                    ServiceMessage::LogEntry { level: _, message } => {
+                        println!("{message}");
+                    }
+                    ServiceMessage::TaskComplete { success: _, summary } => {
+                        println!("{summary}");
+                        return Ok(());
+                    }
+                    ServiceMessage::Busy { message } => return Err(message),
+                }
+            }
+            Message::Close(_) => return Err("service disconnected before task completion".to_string()),
+            _ => {}
+        }
+    }
+}