Add make fmt target and fix gofumpt formatting

Co-Authored-By: Claude (claude-opus-4-6) <noreply@anthropic.com>

Makefile

@@ -49,6 +49,10 @@ air: ## Install air for hot reload.
 dev: air ## run the application with hot reload
 	air --build.cmd "make build" --build.bin ./gitea-mcp
 
+.PHONY: fmt
+fmt: ## format Go code with gofumpt
+	$(GO) run $(GOFUMPT_PACKAGE) -w .
+
 .PHONY: lint
 lint: lint-go ## lint everything
 

operation/pull/pull_test.go

@@ -304,13 +304,13 @@ func Test_mergePullRequestFn_newParams(t *testing.T) {
 	req := mcp.CallToolRequest{
 		Params: mcp.CallToolParams{
 			Arguments: map[string]any{
-				"owner":                      owner,
-				"repo":                       repo,
-				"index":                      float64(index),
-				"merge_style":                "merge",
-				"force_merge":                true,
-				"merge_when_checks_succeed":  true,
-				"head_commit_id":             "abc123",
+				"owner":                     owner,
+				"repo":                      repo,
+				"index":                     float64(index),
+				"merge_style":               "merge",
+				"force_merge":               true,
+				"merge_when_checks_succeed": true,
+				"head_commit_id":            "abc123",
 			},
 		},
 	}