Approve or reject pending tree submissions

## 🧑‍💼 Role
**Verifier**

## 📝 Description
As a verifier,
I want to approve or reject a pending tree
So that it is recorded on-chain and the user is rewarded or notified accordingly.

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## ✅ Acceptance Criteria

- [ ] Approving a tree invokes chaincode:
`VerifyTree(treeID, notes)`
- [ ] Rejecting a tree invokes chaincode:
`RejectTree(treeID, reason)`
- [ ] Peer node validates the verifier's role via **certificate attributes (CID)**

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## 🔧 Sub-tasks

- [ ] Implement **Approve** and **Reject** buttons in the UI
- [ ] Display a **feedback form** to collect:
- Notes (for approval)
- Rejection reason (for rejection)
- [ ] Trigger **chaincode invoke** based on action
- [ ] Show **confirmation dialog** and success/failure feedback

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## 📅 Sprint Info

| Attribute | Value |
|----------------|--------------------|
| **Sprint** | 3 |
| **Priority** | High |
| **Assignee** | Frontend Dev |
| **Story Points**| 8 |

Start by locating the pending-tree UI and the existing chaincode invocation entry point. Add approve and reject actions with their feedback forms, confirmation and result states, then verify that VerifyTree and RejectTree are invoked with the required values and that the peer validates the verifier certificate attributes.

Written by the indexing model from the issue text.