chore(cli): delete the unused processService/processRegionRecommendations purchase path (no confirmation since #2105) #2110

Found in the review of #2105. cmd/multi_service_helpers.go ~431: the legacy processService -> processRegionRecommendations path relied on processPurchaseLoop's per-region confirmation, which #2105 removed in favour of a single up-front confirmPurchaseRun. The path has no production caller (tests only), so this is latent, but if anything calls it again it would purchase with no confirmation. Delete it (and its tests), or route it through confirmPurchaseRun. Also consider: the #2105 test covers only decline/non-TTY; add a SkipConfirmation=true multi-region case asserting totals.