feat(login): add status command (#1087) (#1105)

Implements #1087.

Adds `tea login status [<login name>] [-o <format>]`, which verifies the stored token for one or all configured logins and reports:

- login name/URL and default status
- whether the token is valid (via `GET /api/v1/user`)
- auth method and token expiry
- whether the git credential helper is configured

Machine-readable output is available via the usual `-o` formats with fields `name`, `url`, `user`, `valid`, `auth_method`, `token_expiry`, `helper`, and `default`.

Reviewed-on: https://gitea.com/gitea/tea/pulls/1105
Reviewed-by: bircni <bircni@icloud.com>

modules/task/login_status.go

@@ -0,0 +1,67 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package task
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"gitea.dev/tea/modules/config"
+	"gitea.dev/tea/modules/print"
+)
+
+// CheckLoginStatus verifies the stored token for a login against the server and
+// returns a printable status. Unlike config.Login.Client, refresh failures are
+// captured in the returned status instead of terminating the process.
+func CheckLoginStatus(ctx context.Context, login *config.Login) print.LoginStatus {
+	status := print.LoginStatus{
+		Name:        login.Name,
+		URL:         login.URL,
+		AuthMethod:  loginAuthMethod(login),
+		TokenExpiry: loginTokenExpiry(login),
+		Helper:      HasGitCredentialHelper(*login),
+		Default:     login.Default,
+	}
+
+	if login.GetAccessToken() == "" {
+		status.Error = "Login failed: no access token configured"
+		return status
+	}
+
+	if err := login.RefreshOAuthTokenIfNeeded(); err != nil {
+		status.Error = "Token refresh failed: " + strings.TrimPrefix(err.Error(), "failed to refresh token: ")
+		return status
+	}
+
+	// A successful refresh updates the token in the secure store, so re-read the
+	// expiry for the status line.
+	status.TokenExpiry = loginTokenExpiry(login)
+
+	user, _, err := login.ClientWithoutRefresh().Users.GetMyUserInfo(ctx)
+	if err != nil {
+		status.Error = fmt.Sprintf("Login failed: %s", err)
+		return status
+	}
+
+	status.Valid = true
+	status.User = user.UserName
+	return status
+}
+
+func loginAuthMethod(login *config.Login) string {
+	if login.IsOAuth() {
+		return config.AuthMethodOAuth
+	}
+	return "token"
+}
+
+func loginTokenExpiry(login *config.Login) time.Time {
+	expiry := login.GetTokenExpiry()
+	if expiry.Equal(time.Unix(0, 0)) {
+		return time.Time{}
+	}
+	return expiry
+}