[dong][FE][P2P] #563 Cancel offer API

[potatoArthurDo]

#563

General

• No unnecessary files, debug logs, or commented code included.
• PR has at least 1 peer approval before senior review.
• I fully understand the code I submitted.
• No hardcoded configuration or secrets.
• Environment Variables changes? (Leave unchecked if N/A)

Design & Solution Clarity

• A design diagram (sequence / flow) is attached or linked.
• The implementation matches the design.
• All major flows and decision points are represented in the diagram.
• Error handling and edge cases are clearly defined in the design.

Design link (diagram / doc):
<paste link here>

Testing

• Unit tests cover main logic and important edge cases.

Note: Complex logic must not rely on manual testing only.

Peer Review Checklist

• I understand the overall solution and flow.
• The code follows the provided design diagram.
• No obvious logic or security issues found.
• Tests are sufficient for the scope of this change.

[hoangdohuy]

LGTM