docs: clarify fees collection process in technical flow diagrams

Updated the technical flow diagrams to specify that fees are collected on the origin chain from any remaining balance during the fallback refund path, even if the transaction fails. This change enhances the understanding of the fee structure in failure scenarios.

Author: shunkakinoki

docs/technical-flow-diagrams.md

@@ -431,7 +431,7 @@ sequenceDiagram
 
 - **errorFlag:** The Calls module sets this when a call reverts with `behaviorOnError = IGNORE`
 - **onlyFallback logic:** These calls only run if the previous call reverted
-- **Fees on failure:** Yeah, we still collect fees even when things go wrong
+- **Fees on failure:** Fees are collected on the origin chain from any remaining balance during the fallback refund path, even if the transaction fails.
 - **Partial refunds:** If there's not enough balance for the full refund, we send what's there and emit `ActualRefund`
 - **Atomicity:** Everything happens in one transaction—no way to double-spend