smite: add transaction block position lookup to BitcoinCli

[devvaansh]

Adds BitcoinCli::get_transaction_block_position, which returns the (block_height, tx_index) pair for a confirmed transaction by issuing getrawtransaction followed by getblock. Returns None for unconfirmed or unknown transactions.

This is the missing piece needed to derive a BOLT 7 short_channel_id from a mined 2-of-2 P2WSH funding output, and is a prerequisite for the LookupShortChannelId IR operation that will let ChannelAnnouncementGenerator pass on-chain UTXO validation in CLN and LND.

Ref: #71

[NishantBansal2003]

ACK

I assume that, with this, we’re only left with operation like ComputeShortChannelId, which resolve a funding tx, retrieve its block height and tx index, and compute the SCID from them? In that case, we also need to handle the case where the funding tx hasn't been confirmed yet

[devvaansh]

ACK

I assume that, with this, we’re only left with operation like ComputeShortChannelId, which resolve a funding tx, retrieve its block height and tx index, and compute the SCID from them? In that case, we also need to handle the case where the funding tx hasn't been confirmed yet

Yes, next PR adds LookupShortChannelId (input: FundingTransaction → output: ShortChannelId). The generator always emits BroadcastTransaction → MineBlocks(6) → LookupShortChannelId in sequence, so the tx is confirmed by the time the op executes. If a mutator deletes MineBlocks, get_transaction_block_position returns None and the executor panics, same behaviour as any other broken program (type mismatch, bad variable ref, etc.). No special handling needed.

[NishantBansal2003]

Yes, next PR adds LookupShortChannelId (input: FundingTransaction → output: ShortChannelId). The generator always emits BroadcastTransaction → MineBlocks(6) → LookupShortChannelId in sequence, so the tx is confirmed by the time the op executes. If a mutator deletes MineBlocks, get_transaction_block_position returns None and the executor panics, same behaviour as any other broken program (type mismatch, bad variable ref, etc.). No special handling needed.

I don’t think we should make the generator mine a specific number of blocks. I think we should keep it as a range, like rng.random_range(1..=16), in the generator as well

If the tx is not confirmed, that's still a valid program, so it shouldn't panic. smite should only panic when the program (generated by smite) is invalid, in which case it’s a bug that should be fixed in smite-ir itself

[morehouse]

Please squash to a single commit.

[morehouse]

We now have two functions that call getrawtransaction. It would seem natural to have a private helper that returns the GetRawTransactionResponse.

[morehouse]

It might be good to explicitly set verbosity=1 so that this doesn't break if the default verbosity ever changes.