feat(users): passwordless user creation via emailed set-password link, display full name instead of username

Admins now create users with a name + email (no password) and role;
a Send Email action (per-user, also reusable for resets) issues a
one-time token and POSTs it to an admin-configurable webhook URL —
intended for a Power Automate flow that delivers the actual email.
The old admin-sets-the-password flow is kept server-side
(LegacyUserCreateWithPassword) but no longer wired into the UI.

Every user-facing surface (top bar, sidebar, user management, audit
log, assignee pickers, dispute notifications) now shows full_name
instead of username, falling back to username when unset.

Also fixes long attack_procedure/expected_detection/suggested_text
text overflowing its container in the template review panels and
Red/Blue team fields (missing break-words on whitespace-pre-wrap
blocks).

backend/app/models/user.py

@@ -30,6 +30,9 @@ class User(Base):
     username = Column(String, unique=True, nullable=False)
     # Assign email = Column(String, nullable=True)
     email = Column(String, nullable=True)
+    # Display name shown everywhere in the UI instead of username (which is
+    # now just an internal login identifier, auto-set to the user's email).
+    full_name = Column(String, nullable=True)
     # Assign hashed_password = Column(String, nullable=False)
     hashed_password = Column(String, nullable=False)
     # Assign role = Column(String, nullable=False, default="viewer")