Fix spacetime login --token falling through to web login (#4579)

## Bug

PR #4367 (login/logout UX overhaul) accidentally removed the early
`return Ok(())` after saving a token via `spacetime login --token`. This
caused the command to fall through into the web login flow
(`spacetimedb_login_and_save`), which fails when no browser or server is
available.

## Impact

All tests that use `spacetime login --token` are broken:
- 4 replication tests (`test_enable_disable_replication`,
`test_enable_replication_on_suspended_database`,
`test_enable_replication_fails_if_not_suspended`, `test_prefer_leader`)
- 5 teams tests (`test_permissions_clear_org`,
`test_permissions_delete_org`,
`test_org_permissions_mut_sql_org_members`,
`test_org_permissions_private_tables`,
`test_permissions_publish_org_members`)

## Fix

One line: restore `return Ok(())` after the `--token` branch.

---------

Signed-off-by: Zeke Foppa <196249+bfops@users.noreply.github.com>
Co-authored-by: clockwork-labs-bot <clockwork-labs-bot@users.noreply.github.com>
Co-authored-by: Zeke Foppa <bfops@users.noreply.github.com>
Co-authored-by: Zeke Foppa <196249+bfops@users.noreply.github.com>

crates/cli/src/subcommands/login.rs

@@ -71,6 +71,7 @@ pub async fn exec(mut config: Config, args: &ArgMatches) -> Result<(), anyhow::E
             Ok(identity) => println!("Logged in with identity {identity}"),
             Err(_) => println!("Token saved."),
         }
+        return Ok(());
     }
 
     if let Some(server) = server_issued_login {

crates/smoketests/tests/smoketests/cli/auth.rs

@@ -3,6 +3,7 @@
 use spacetimedb_smoketests::{require_local_server, Smoketest};
 use std::fs;
 use std::process::Output;
+use std::time::{Duration, Instant};
 
 fn output_stdout(output: &Output) -> String {
     String::from_utf8_lossy(&output.stdout).to_string()
@@ -170,3 +171,62 @@ fn cli_logging_in_twice_works() {
         second_stdout
     );
 }
+
+fn try_until_timeout<F: FnMut() -> Option<R>, R>(timeout: Duration, mut f: F) -> Option<R> {
+    let start = Instant::now();
+    loop {
+        match f() {
+            Some(result) => return Some(result),
+            None => {
+                if start.elapsed() > timeout {
+                    return None;
+                }
+                std::thread::sleep(std::time::Duration::from_millis(200));
+            }
+        }
+    }
+}
+
+/// Test that `spacetime login --token <token>` exits immediately after saving
+/// the token, without falling through to the interactive web login flow.
+///
+/// Without the fix in PR #4579, the command would fall through to the web
+/// login flow, which hangs waiting for a browser callback.
+#[test]
+fn cli_login_with_token() {
+    use std::io::Read;
+    use std::process::{Command, Stdio};
+
+    let test = Smoketest::builder().autopublish(false).build();
+    let cli_path = spacetimedb_guard::ensure_binaries_built();
+
+    let mut child = Command::new(&cli_path)
+        .arg("--config-path")
+        .arg(&test.config_path)
+        .args(["login", "--token", "test-dummy-token", "--no-browser"])
+        .env_remove("BROWSER")
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .expect("Failed to spawn spacetime login");
+
+    // Run with timeout in case something goes wrong and it tries to open the browser for login.
+    let timeout = Duration::from_secs(5);
+    let Some(status) = try_until_timeout(timeout, || child.try_wait().expect("Failed to poll child")) else {
+        child.kill().ok();
+        panic!(
+            "spacetime login --token hung for >{timeout:?} — \
+            likely fell through to web login flow"
+        );
+    };
+    let mut stdout = String::new();
+    child.stdout.take().unwrap().read_to_string(&mut stdout).unwrap();
+    assert!(
+        status.success(),
+        "spacetime login --token failed (exit {status}):\n{stdout}"
+    );
+    assert!(
+        stdout.contains("Token saved."),
+        "Expected 'Token saved.' in output, got: {stdout}"
+    );
+}