From, say, the Russo-Japanese war onwards, was there any naval doctrine that considered the possibility of a combat capture of a major vessel, from a light cruiser on up?
I am only familiar with very specific examples, such as the capture of the crippled Italian cruiser Pola after the battle of Cape Matapan, or the boarding of U-570 - both of which had either surrendered or simply weren't resisting prior to being boarded.
Is there any situation in which this would have been doable, either opportunistically or with dedicated, prepared boarding parties?
The only instance I can find of an ironclad-and-later-era boarding under fire of a large ship is during the War of the Pacific.
Not really. Capture of sailing vessels was common because actually sinking a wooden ship with cannon fire is difficult. Wood floats and even taking on water its easy to keep positive buoyancy. Combine that with the realities of inaccurate cannon and it was easier to destroy rigging and them board and capture the ship.
This is not true of modern steel warships. It is very difficult to disable a ship's propulsion without sinking it and it is relatively easier to actually sink a ship and not just disable it. Steel doesn't float. Also trying to board a hostile ship is suicide because even if you could get close enough through all the fire they have machine guns to mow down any people boarding.
I guess it is possible it may have happened but I don't know of any off the top of my head.