Integrate ceiling fixture into Hue system
and then wiring the Hue smart plug into the ceiling via the exposed
wires.

What?, Exposed wires, NO.
You would have to have an outlet with the Hue smart plug installed and then plug the modified chandelier wire into the Hue smart outlet. That will only turn it off and on, not control brightness, tone and color like with the Hue bulbs.

The only option I am aware of

How about their smart dimmer switch?
They DO have a E12 base candelabra bulb.
You could use an E12 to E26 adapter  and use their filament smart bulbs
Or a White and color E26 base bulb in the E12 to E26 adaptor.
Philips Hue