feat: add wrapper for devnet mint endpoint

docs/packages/avnu_provider.mdx

@@ -2,10 +2,10 @@
 
 ## Index
 
-- [I. Introduction](#i-introduction)
-- [II. Functions](#ii-functions)
-- [III. Example](#iii-example)
-- [IV. How to run tests](#iv-how-to-run-tests)
+- [I. Introduction](packages/avnu_provider#i-introduction)
+- [II. Functions](packages/avnu_provider#ii-functions)
+- [III. Example](packages/avnu_provider#iii-example)
+- [IV. How to run tests](packages/avnu_provider#iv-how-to-run-tests)
 
 AVNU Paymaster Provider is a Dart package that provides a way to interact with the AVNU paymaster service.
 
@@ -260,11 +260,10 @@ This is an example of a successful API response:
 
 ## IV. How to run tests
 
-To run the tests, you need to set the environment variables `AVNU_RPC` and `STARKNET_RPC` with the corresponding values.
+To run the tests, you need to set the environment variable for `AVNU_RPC` with the corresponding values.
 
 ```bash
 export AVNU_RPC=https://sepolia.api.avnu.fi
-export STARKNET_RPC=https://starknet-sepolia.public.blastapi.io/rpc/v0_7
 ```
 
 Then, run the tests with the following command:

packages/starknet_provider/dart_test.yaml

@@ -1,2 +1,3 @@
 tags:
   unit:
+  integration:

packages/starknet_provider/lib/src/model/index.dart

@@ -32,3 +32,4 @@ export 'state_update.dart';
 export 'syncing.dart';
 export 'declare_transaction.dart';
 export 'contract_class.dart';
+export 'mint_transaction.dart';

packages/starknet_provider/lib/src/model/mint_transaction.dart

@@ -0,0 +1,42 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'mint_transaction.freezed.dart';
+part 'mint_transaction.g.dart';
+
+/// Parameters for minting tokens
+@freezed
+class MintRequest with _$MintRequest {
+  const factory MintRequest({
+    required String address, // "0x6e3205f..."
+    required int amount, // 500000
+    /// Can be either "WEI" or "FRI"
+    required String unit, // "WEI" | "FRI"
+  }) = _MintRequest;
+
+  factory MintRequest.fromJson(Map<String, dynamic> json) =>
+      _$MintRequestFromJson(json);
+}
+
+/// Response from minting tokens
+@freezed
+class MintResponse with _$MintResponse {
+  const factory MintResponse({
+    required MintResult result,
+  }) = _MintResponse;
+
+  factory MintResponse.fromJson(Map<String, dynamic> json) =>
+      _$MintResponseFromJson(json);
+}
+
+/// Result data from minting tokens
+@freezed
+class MintResult with _$MintResult {
+  const factory MintResult({
+    @JsonKey(name: 'new_balance') required String newBalance,
+    required String unit,
+    @JsonKey(name: 'tx_hash') required String txHash,
+  }) = _MintResult;
+
+  factory MintResult.fromJson(Map<String, dynamic> json) =>
+      _$MintResultFromJson(json);
+}