funding: LQT nullifier set for epoch (#5034)

## Describe your changes

state key for epoch-scoped nullifier set (mapping nullifiers with their
associated transaction id), serving as a precursor for performing the
necessary stateful [nullifier
check](https://github.com/penumbra-zone/penumbra/pull/5033/files#diff-a0986b8d223ab5b1c5536ba06bde1ede6d08f635eb97b386549ecfb55a4f2a4bR112).
Additionally, augments the transaction context with `TransactionId`.

## Issue ticket number and link

references #5029

## Checklist before requesting a review

- [x] I have added guiding text to explain how a reviewer should test
these changes.

- [x] If this code contains consensus-breaking changes, I have added the
"consensus-breaking" label. Otherwise, I declare my belief that there
are not consensus-breaking changes, for the following reason:

  > LQT branch

crates/core/app-tests/tests/spend.rs

@@ -17,7 +17,7 @@ use penumbra_sdk_sct::{
 use penumbra_sdk_shielded_pool::{
     component::ShieldedPool, Note, SpendPlan, SpendProof, SpendProofPrivate, SpendProofPublic,
 };
-use penumbra_sdk_txhash::{EffectHash, TransactionContext};
+use penumbra_sdk_txhash::{EffectHash, TransactionContext, TransactionId};
 use rand_core::{OsRng, SeedableRng};
 use std::{ops::Deref, sync::Arc};
 use tendermint::abci;
@@ -65,6 +65,7 @@ async fn spend_happy_path() -> anyhow::Result<()> {
     let transaction_context = TransactionContext {
         anchor: root,
         effect_hash: EffectHash(dummy_effect_hash),
+        transaction_id: TransactionId([0; 32]),
     };
 
     // 3. Simulate execution of the Spend action
@@ -189,6 +190,7 @@ async fn invalid_dummy_spend() {
     let transaction_context = TransactionContext {
         anchor: root,
         effect_hash: EffectHash(dummy_effect_hash),
+        transaction_id: TransactionId([0; 32]),
     };
 
     // 3. Simulate execution of the Spend action

crates/core/component/funding/src/component.rs

@@ -9,6 +9,7 @@ use penumbra_sdk_asset::{Value, STAKING_TOKEN_ASSET_ID};
 use penumbra_sdk_proto::{DomainType, StateWriteProto};
 use penumbra_sdk_stake::component::validator_handler::ValidatorDataRead;
 pub use view::{StateReadExt, StateWriteExt};
+pub(crate) mod liquidity_tournament;
 
 use std::sync::Arc;
 

crates/core/component/funding/src/component/liquidity_tournament/mod.rs

@@ -0,0 +1 @@
+pub mod nullifier;

crates/core/component/funding/src/component/liquidity_tournament/nullifier/mod.rs

@@ -0,0 +1,53 @@
+use async_trait::async_trait;
+use penumbra_sdk_txhash::TransactionId;
+
+use crate::component::state_key;
+use cnidarium::{StateRead, StateWrite};
+use penumbra_sdk_proto::{StateReadProto, StateWriteProto};
+use penumbra_sdk_sct::{component::clock::EpochRead, Nullifier};
+
+#[allow(dead_code)]
+#[async_trait]
+pub trait NullifierRead: StateRead {
+    /// Returns the `TransactionId` if the nullifier has been spent; otherwise, returns None.
+    async fn get_lqt_spent_nullifier(&self, nullifier: Nullifier) -> Option<TransactionId> {
+        // Grab the ambient epoch index.
+        let epoch_index = self
+            .get_current_epoch()
+            .await
+            .expect("epoch is always set")
+            .index;
+
+        let nullifier_key = &state_key::lqt::v1::nullifier::key(epoch_index, &nullifier);
+
+        let tx_id: Option<TransactionId> = self
+            .nonverifiable_get(&nullifier_key.as_bytes())
+            .await
+            .expect(&format!(
+                "failed to retrieve key {} from non-verifiable storage",
+                nullifier_key,
+            ));
+
+        tx_id
+    }
+}
+
+impl<T: StateRead + ?Sized> NullifierRead for T {}
+
+#[allow(dead_code)]
+#[async_trait]
+pub trait NullifierWrite: StateWrite {
+    /// Sets the LQT nullifier in the NV storage.
+    fn put_lqt_spent_nullifier(
+        &mut self,
+        epoch_index: u64,
+        nullifier: Nullifier,
+        tx_id: TransactionId,
+    ) {
+        let nullifier_key = state_key::lqt::v1::nullifier::key(epoch_index, &nullifier);
+
+        self.nonverifiable_put(nullifier_key.into(), tx_id);
+    }
+}
+
+impl<T: StateWrite + ?Sized> NullifierWrite for T {}

crates/core/component/funding/src/component/state_key.rs

@@ -1,3 +1,16 @@
 pub fn funding_parameters() -> &'static str {
     "funding/parameters"
 }
+
+pub mod lqt {
+    pub mod v1 {
+        pub mod nullifier {
+            use penumbra_sdk_sct::Nullifier;
+
+            /// A nullifier set indexed by epoch, mapping each epoch to its corresponding `TransactionId`.
+            pub(crate) fn key(epoch_index: u64, nullifier: &Nullifier) -> String {
+                format!("funding/lqt/v1/nullifier/{epoch_index:020}/lookup/{nullifier}")
+            }
+        }
+    }
+}

crates/core/component/funding/src/component/view.rs

@@ -1,7 +1,6 @@
-use async_trait::async_trait;
-
 use crate::{component::state_key, params::FundingParameters};
 use anyhow::Result;
+use async_trait::async_trait;
 use cnidarium::{StateRead, StateWrite};
 use penumbra_sdk_proto::{StateReadProto, StateWriteProto};
 

crates/core/transaction/src/transaction.rs

@@ -144,6 +144,7 @@ impl Transaction {
         TransactionContext {
             anchor: self.anchor,
             effect_hash: self.effect_hash(),
+            transaction_id: self.id(),
         }
     }
 

crates/core/txhash/src/context.rs

@@ -1,4 +1,4 @@
-use crate::EffectHash;
+use crate::{EffectHash, TransactionId};
 use penumbra_sdk_tct as tct;
 
 /// Stateless verification context for a transaction.
@@ -10,4 +10,6 @@ pub struct TransactionContext {
     pub anchor: tct::Root,
     /// The transaction's effect hash.
     pub effect_hash: EffectHash,
+    /// The transaction's id.
+    pub transaction_id: TransactionId,
 }