docs: sync SDK docs with agent source + fix numeric validation

- Add 3 missing sdk.ton methods: createJettonTransfer, getPublicKey, getWalletVersion
- Add SignedTransfer type documentation
- Add sdk.bot and sdk.on sections to SKILL.md
- Fix masking count 5 → 10 to match MASKING_KEEP_RECENT_COUNT
- Fix isNaN → Number.isFinite in dedust, stonfi, swapcoffee, multisend