Fix coin-ops blocked by shared Direct maker p2 watches

[hoffmang9]

Summary

• Direct maker_puzzle_hash is the vault inventory CAT outer / receive inner; seeding it as a per-offer kind='p2' watch locked every coin of that asset and blocked combine/split (no_spendable_combine_coin_available).
• Coin-ops now excludes spendable coins by durable coin-id watches only; per-offer p2 watches are seeded only when cancel metadata is is_presplit_like (explicit Presplit, or legacy NULL mode + fixed_delegated_puzzle_hash).
• Heal/Dexie/post share that gate with cancel policy; ADR 0019 updated to match.

Test plan

• cargo test --lib execute_managed_coin_op (coin-id exclusion / p2 ignored)
• cargo test --lib classify_heals (Direct coin-only; NULL-mode presplit seeds CONDITIONS p2)
• cargo test --lib is_presplit_like
• cargo test --lib offer_post_persist_record (Direct watched_p2s empty)
• On john-deere (or similar): with open Direct BYC sells, confirm combine plans execute instead of no_spendable_combine_coin_available