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/routers/auth.py

@@ -57,7 +57,7 @@ from app.models.user import User
 from app.schemas.auth import TokenResponse, UserOut
 
 # Import PasswordChange from app.schemas.user
-from app.schemas.user import PasswordChange
+from app.schemas.user import PasswordChange, SetPasswordRequest, SetPasswordTokenValidateOut
 
 # Import log_action from app.services.audit_service
 from app.services.audit_service import log_action
@@ -72,6 +72,12 @@ from app.services.auth_service import (
     change_password as auth_change_password,
 )
 
+from app.domain.errors import EntityNotFoundError
+from app.services.password_setup_service import (
+    consume_token_and_set_password,
+    validate_token as validate_password_setup_token,
+)
+
 # Assign router = APIRouter(prefix="/auth", tags=["auth"])
 router = APIRouter(prefix="/auth", tags=["auth"])
 
@@ -381,3 +387,37 @@ def change_password(
 
     # Return {"detail": "Password changed successfully"}
     return {"detail": "Password changed successfully"}
+
+
+# ---------------------------------------------------------------------------
+# Set password via a one-time emailed link — public (no auth), rate-limited
+# ---------------------------------------------------------------------------
+
+
+@router.get("/set-password/validate", response_model=SetPasswordTokenValidateOut)
+@limiter.limit("20/minute")
+def validate_set_password_token(request: Request, token: str, db: Session = Depends(get_db)) -> SetPasswordTokenValidateOut:
+    """Check a set-password token before rendering the form. Public endpoint."""
+    try:
+        user = validate_password_setup_token(db, token)
+    except (EntityNotFoundError, BusinessRuleViolation):
+        return SetPasswordTokenValidateOut(valid=False)
+    return SetPasswordTokenValidateOut(valid=True, full_name=user.full_name)
+
+
+@router.post("/set-password")
+@limiter.limit("10/minute")
+def set_password(request: Request, body: SetPasswordRequest, db: Session = Depends(get_db)) -> dict:
+    """Complete a password setup/reset using a one-time token. Public endpoint."""
+    with UnitOfWork(db) as uow:
+        user = consume_token_and_set_password(db, body.token, body.new_password)
+        log_action(
+            db,
+            user.id,
+            "SET_PASSWORD_VIA_TOKEN",
+            "auth",
+            str(user.id),
+            details={},
+        )
+        uow.commit()
+    return {"detail": "Password set successfully — you can now log in"}