Issue #3622616: Follow kessai's rename across the payment client, the handoff argument and deleteStoredTokens()

Implements #3622616.

Two call sites follow kessai #3621923: PaymentManagerInterface::deleteStoredCard() becomes deleteStoredTokens(), because what the engine holds is a token and the human at the other end is the payer. The wording immediately around each call follows, in the transaction predelete hook and in the immediate delete action.

Nothing else here is affected: the two base fields kessai renames are never read in yoyaku, every other method it calls on the payment manager stays where it is, and yoyaku builds no handoff link of its own.

yoyaku's own card words are deliberately untouched: DeleteCardAction, its yoyaku_delete_card plugin id and CardTokenMatcher are its names for its own things, one of them is in shipped configuration, and kessai's rename does not reach them.

CI will be red until kessai lands, and that is the point

deleteStoredTokens() exists only on kessai's 3621923 branch. The pipeline installs kessai from its released alpha, so phpstan and phpunit cannot resolve it. The three merge requests have to land together — kessai !68 (merged), this, and orchestra #3622615 — and kessai's two renamed base fields mean the site is reinstalled when they do.

Verified here instead: phpcs at the templates' own ruleset is clean over the whole module, and the new name was checked against its declaration on kessai's branch.

AI-Generated: Yes (Claude Code was used to help write this change and its merge request description. I reviewed and ran the work myself before posting it.)