Adds an "M365 Login" menu entry with a Microsoft-style icon and one
submenu per tab (Connection, Button, Security). The active tab is taken
from the URL, kept in the post-save redirect and highlighted in the
submenu. Notices are printed explicitly because top-level pages do not
include options-head.php. Links, docs and screenshots updated.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJxAHYdMfKPoN4koRc4Ci2
Login page (default and button-only mode) and the three settings tabs,
rendered from the plugin's own markup and CSS inside a mock WordPress
admin shell.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJxAHYdMfKPoN4koRc4Ci2
