Feat/public fee estimation

[thomas-kroes]

No description provided.

[greptile-apps]

Greptile Summary

This PR adds a public estimateTransactionFee method to NockchainProvider, exposing the nock_estimateTransactionFee RPC call as a read-only, no-popup way for dApps to preview the network fee before submitting a send. The change also makes fee optional on SendTransactionRequest so the wallet can auto-calculate it when omitted.

• Adds ESTIMATE_TRANSACTION_FEE to PROVIDER_METHODS and EstimateTransactionFeeRequest/EstimateTransactionFeeResponse to src/types.ts, then wires them up with the new estimateTransactionFee method in src/provider.ts following the same guard-and-request pattern as sendTransaction and signTx.
• Bumps the package version from 0.2.0 to 0.3.0, consistent with a new public API being added.

Confidence Score: 4/5

The change is a straightforward, additive feature with no modifications to existing logic; safe to merge.

The new method follows the same connect-guard → RPC-dispatch pattern as every other provider method and introduces no shared mutable state. The only thing worth a second look is a minor documentation inconsistency in the amount field comment on EstimateTransactionFeeRequest.

src/types.ts — the EstimateTransactionFeeRequest.amount JSDoc comment should match the more descriptive wording used on the same field in SendTransactionRequest.

Important Files Changed

Filename	Overview
src/provider.ts	Adds estimateTransactionFee method following the same guard-and-request pattern as sendTransaction and signTx; well-documented with JSDoc
src/types.ts	Adds EstimateTransactionFeeRequest and EstimateTransactionFeeResponse interfaces; EstimateTransactionFeeRequest.amount comment is less descriptive than the parallel field in SendTransactionRequest
src/constants.ts	Adds ESTIMATE_TRANSACTION_FEE constant to PROVIDER_METHODS; clean addition consistent with existing constants
package.json	Version bump from 0.2.0 to 0.3.0 — appropriate for a new public API addition

Sequence Diagram

sequenceDiagram
    participant dApp
    participant NockchainProvider
    participant InjectedNockchain as window.nockchain

    dApp->>NockchainProvider: "estimateTransactionFee({ to, amount })"
    alt not connected
        NockchainProvider-->>dApp: throw NoAccountError
    else connected
        NockchainProvider->>InjectedNockchain: "request({ method: 'nock_estimateTransactionFee', params, api: '1.0.0' })"
        alt wallet locked / no UTXOs / API 0 wallet
            InjectedNockchain-->>NockchainProvider: RPC error
            NockchainProvider-->>dApp: throw RpcError
        else success
            InjectedNockchain-->>NockchainProvider: "EstimateTransactionFeeResponse { fee }"
            NockchainProvider-->>dApp: "EstimateTransactionFeeResponse { fee }"
        end
    end

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Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
src/types.ts:95-100
The `amount` field on `EstimateTransactionFeeRequest` omits the accepted-type note that appears on the parallel field in `SendTransactionRequest`. Since both fields carry the same `Nicks` type and the same runtime coercion rules apply, users consulting one interface but not the other may not know that legacy numbers and bigints are also accepted.

```suggestion
export interface EstimateTransactionFeeRequest {
  /** Recipient address (base58-encoded public key hash / PKH) */
  to: Address;
  /** Amount to send in nicks (legacy number + canonical string/bigint accepted) */
  amount: Nicks;
}
```

_{Reviews (1): Last reviewed commit: "chore: bump version to 0.3.0" | Re-trigger Greptile}