docs: rustdoc for receipt-shard's exported names and BuybackConfiguredEvent's fields (#749, #790)

CHANGELOG.md

@@ -26,6 +26,9 @@ breaking changes bump the **minor** version, and they are called out as such.
   accepts an optional `coupon_id` parameter; when provided, the discount is applied
   atomically before the token transfer. Added error codes `CouponNotFound` and
   `CouponAlreadyRedeemed` to the common Error enum.
+- docs: rustdoc for `receipt-shard`'s 4 exported names (#749) and for the 5
+  public fields of `BuybackConfiguredEvent` (#790). Doc comments only — no
+  signature, struct layout or behaviour change.
 
 ### Added
 - **`privacy` (issue #440): Groth16 verification for concealed escrow amounts.**

ROADMAP.md

@@ -8,6 +8,15 @@
   - Exchange rate progression and lock-epoch-based redemption
   - CHANGELOG.md entry added
 
+## Issue #749: rustdoc for receipt-shard's 4 exported names
+
+- [x] Document `DataKey`, `ReceiptShard`, `get_batch` and `extend_batch_ttl` (#749)
+  - `contracts/receipt-shard/src/lib.rs` — doc comments only, no signature, body or test changes
+
+## Issue #790: rustdoc for `BuybackConfiguredEvent`'s 5 public fields
+
+- [x] Document the struct's 5 public fields (#790)
+  - `contracts/treasury/src/buyback.rs` — doc comments only, field/type/order/derives unchanged
 ## Issue #663: Reconcile immutability claims with refund-vault's upgrade_wasm
 
 - [x] Reconcile immutability claims with refund-vault's upgrade_wasm (#663)

contracts/receipt-shard/src/lib.rs

@@ -21,6 +21,7 @@ contractmeta!(
 );
 contractmeta!(key = "commit", val = env!("GIT_SHA"));
 
+/// Storage keys for this shard's instance state and its per-batch records.
 #[contracttype]
 pub enum DataKey {
     Router,
@@ -66,6 +67,9 @@ const TTL_THRESHOLD: u32 = 100;
 /// MAX_BATCH_SIZE = 1000 (router constant), that is 10.
 const MAX_PROOF_LEN: u32 = 10;
 
+/// A storage shard: holds the batch records for one `[start_batch_id,
+/// end_batch_id)` slice of a router's batch stream. Every state-changing
+/// entry point authenticates the `router` address recorded at construction.
 #[contract]
 pub struct ReceiptShard;
 
@@ -140,6 +144,10 @@ impl ReceiptShard {
             .extend_ttl(&DataKey::Batch(batch_id), TTL_THRESHOLD, TTL_EXTEND);
     }
 
+    /// Reads this shard's record for `batch_id`. Read-only and
+    /// unauthenticated. Returns `Error::BatchNotFound` when the shard holds no
+    /// record for that id — because it was never anchored, or because
+    /// `prune_batches` already deleted it.
     pub fn get_batch(env: Env, batch_id: u64) -> Result<BatchRecord, Error> {
         env.storage()
             .persistent()
@@ -183,6 +191,10 @@ impl ReceiptShard {
         computed_hash
     }
 
+    /// Extends the TTL of the batch record at `batch_id` so an unpruned record
+    /// stays live. Publicly callable, no auth and no caller precondition except
+    /// that the shard is still active (an inactive shard panics). Returns
+    /// `Error::BatchNotFound` when the shard holds no record for that id.
     pub fn extend_batch_ttl(env: Env, batch_id: u64) -> Result<(), Error> {
         assert!(Self::is_active(env.clone()), "shard is inactive");
         if !env.storage().persistent().has(&DataKey::Batch(batch_id)) {

contracts/treasury/src/buyback.rs

@@ -63,12 +63,22 @@ pub struct BuybackConfig {
 #[contractevent]
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct BuybackConfiguredEvent {
+    /// Token the treasury spends; written by `set_buyback_config` and published
+    /// as an event topic.
     #[topic]
     pub fee_token: Address,
+    /// Token the treasury buys back and burns; written by `set_buyback_config`
+    /// and published as an event topic.
     #[topic]
     pub governance_token: Address,
+    /// Router the swap is sent to; written by `set_buyback_config` and carried
+    /// in the event data.
     pub router: Address,
+    /// Destination the bought governance tokens are sent to; written by
+    /// `set_buyback_config`.
     pub burn_address: Address,
+    /// Smallest swap `execute_buyback` will perform, in fee-token units;
+    /// written by `set_buyback_config`.
     pub min_amount_in: i128,
 }