feat: implement Fiat Off-Ramp Settlement Event (#1046)

* feat: implement Fiat Off-Ramp Settlement Event

- Add FiatPayoutRequested event emission (F_PAYOUT) in claim_inheritance_plan
- Event contains plan_id, beneficiary_index, amount, and fiat_anchor_info
- Only emitted when beneficiary has non-empty bank_account
- Sensitive bank_account data stored as Bytes for off-chain lookup

Closes #1043

* fix: use is_empty() instead of len() > 0 to satisfy Clippy

---------

Co-authored-by: Yasir Abdulsalam <donyasikd0609@gmail.com>

Author: Yasir-TechGuy

contracts/inheritance-contract/src/lib.rs

@@ -2520,6 +2520,16 @@ impl InheritanceContract {
             (plan_id, hashed_email, payout),
         );
 
+        // Emit FiatPayoutRequested event if beneficiary has bank_account (fiat settlement)
+        let beneficiary = plan.beneficiaries.get(index).unwrap();
+        if !beneficiary.bank_account.is_empty() {
+            // fiat_anchor_info = "BANK" indicates bank transfer settlement
+            env.events().publish(
+                (symbol_short!("F_PAYOUT"),),
+                (plan_id, index, payout, symbol_short!("BANK")),
+            );
+        }
+
         log!(
             &env,
             "Inheritance claimed for plan {} by {}",