fix(contracts): guard maintenance logging; add pause, record amend/void, and WASM allowlist

contracts/ERRORS.md

@@ -75,6 +75,27 @@ code 1 across different contracts.
 | 170–179 | Validation |
 | 180–199 | Leasing and insurance |
 
+The enum is capped at **50 cases** by the contract spec, so narrow
+single-subject variants were folded into generic ones. The following codes are
+retired and must not be reused:
+
+| Retired code | Former variant | Now returns |
+|---:|---|---|
+| 103 | `BranchAlreadyExists` | `AlreadyExists` (101) |
+| 104 | `BranchNotFound` | `NotFound` (5) |
+| 105 | `SubscriptionAlreadyExists` | `AlreadyExists` (101) |
+| 123 | `InvalidTokenDecimals` | `InvalidInput` (4) |
+| 142 | `ProposalNotFound` | `NotFound` (5) |
+| 170 | `InvalidAssetName` | `InvalidInput` (4) |
+| 171 | `InvalidPurchaseValue` | `InvalidInput` (4) |
+| 172 | `InvalidMetadataUri` | `InvalidInput` (4) |
+| 180 | `LeaseNotFound` | `NotFound` (5) |
+| 181 | `LeaseAlreadyExists` | `AlreadyExists` (101) |
+| 194 | `PolicyAlreadyExists` | `AlreadyExists` (101) |
+| 195 | `ClaimAlreadyExists` | `AlreadyExists` (101) |
+
+Code `101` was renamed from `AssetAlreadyExists` to `AlreadyExists`.
+
 ## `contrib` (200–299)
 
 Typed `Error` enum lives in `contrib/src/error.rs` and is wired into the crate.
@@ -114,6 +135,7 @@ Typed `Error` enum lives in `asset-maintenance/src/error.rs`. Failures use
 | Block | Concern |
 |---:|---|
 | 500–509 | Providers, schedules, warranties, alerts |
+| 510–513 | Maintenance records (voiding/amending) and detokenized assets |
 
 ## For backend implementers
 

contracts/asset-maintenance/src/error.rs

@@ -42,6 +42,14 @@ pub enum Error {
     AssetNotFound = 508,
     /// Invalid date / cost / rating arguments.
     InvalidArguments = 509,
+    /// A record that has already been voided cannot be voided again.
+    RecordAlreadyVoided = 510,
+    /// No maintenance record with that id exists for the asset.
+    RecordNotFound = 511,
+    /// A voided record can no longer be amended.
+    RecordVoided = 512,
+    /// The asset has been detokenized/burned and accepts no new maintenance.
+    AssetDetokenized = 513,
 }
 
 pub fn handle_error(env: &Env, error: Error) -> ! {
@@ -67,6 +75,10 @@ mod tests {
             Error::AlertIndexOutOfBounds as u32,
             Error::AssetNotFound as u32,
             Error::InvalidArguments as u32,
+            Error::RecordAlreadyVoided as u32,
+            Error::RecordNotFound as u32,
+            Error::RecordVoided as u32,
+            Error::AssetDetokenized as u32,
         ] {
             assert!((500..600).contains(&code));
         }

contracts/asset-maintenance/src/events.rs

@@ -5,7 +5,7 @@
 //! `lower_snake_case`. `asset_id` is always a `#[topic]` so consumers can index
 //! per asset.
 
-use soroban_sdk::{contractevent, Address, Env};
+use soroban_sdk::{contractevent, Address, Env, String};
 
 use crate::{AlertSeverity, AlertType, MaintenanceAlert, MaintenanceRecord, ScheduledMaintenance};
 
@@ -141,6 +141,66 @@ pub struct AlertAcknowledged {
     pub timestamp: u64,
 }
 
+/// The contract was paused; new maintenance records now reject.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ContractPaused {
+    #[topic]
+    pub admin: Address,
+    pub timestamp: u64,
+}
+
+/// The contract was unpaused and resumed normal operation.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ContractUnpaused {
+    #[topic]
+    pub admin: Address,
+    pub timestamp: u64,
+}
+
+/// A previously recorded maintenance entry was voided.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct MaintenanceRecordVoided {
+    #[topic]
+    pub asset_id: u64,
+    pub record_id: u64,
+    pub voided_by: Address,
+    pub timestamp: u64,
+}
+
+/// A previously recorded maintenance entry was amended.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct MaintenanceRecordAmended {
+    #[topic]
+    pub asset_id: u64,
+    pub record_id: u64,
+    pub amended_by: Address,
+    pub timestamp: u64,
+}
+
+/// An asset was marked detokenized/burned and accepts no new maintenance.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct AssetDetokenized {
+    #[topic]
+    pub asset_id: u64,
+    pub admin: Address,
+    pub timestamp: u64,
+}
+
+/// A detokenized asset was reactivated.
+#[contractevent]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct AssetReactivated {
+    #[topic]
+    pub asset_id: u64,
+    pub admin: Address,
+    pub timestamp: u64,
+}
+
 // ---------------------------------------------------------------------------
 // Emission helpers
 // ---------------------------------------------------------------------------
@@ -263,3 +323,57 @@ pub fn alert_acknowledged(env: &Env, asset_id: u64, alert_index: u32, by: &Addre
     }
     .publish(env);
 }
+
+pub fn contract_paused(env: &Env, admin: &Address) {
+    ContractPaused {
+        admin: admin.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}
+
+pub fn contract_unpaused(env: &Env, admin: &Address) {
+    ContractUnpaused {
+        admin: admin.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}
+
+pub fn maintenance_record_voided(env: &Env, asset_id: u64, record_id: u64, by: &Address) {
+    MaintenanceRecordVoided {
+        asset_id,
+        record_id,
+        voided_by: by.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}
+
+pub fn maintenance_record_amended(env: &Env, asset_id: u64, record_id: u64, by: &Address) {
+    MaintenanceRecordAmended {
+        asset_id,
+        record_id,
+        amended_by: by.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}
+
+pub fn asset_detokenized(env: &Env, asset_id: u64, admin: &Address) {
+    AssetDetokenized {
+        asset_id,
+        admin: admin.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}
+
+pub fn asset_reactivated(env: &Env, asset_id: u64, admin: &Address) {
+    AssetReactivated {
+        asset_id,
+        admin: admin.clone(),
+        timestamp: env.ledger().timestamp(),
+    }
+    .publish(env);
+}