test: update E2E test to use build directory and fix linter issues

.gitignore

@@ -1,5 +1,5 @@
 # Binaries
-toolbox
+build/
 *.exe
 *.exe~
 *.dll

cmd/toolbox/main_test.go

@@ -0,0 +1,160 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"os/exec"
+	"testing"
+	"time"
+)
+
+const (
+	testPort = "9999"
+	baseURL  = "http://localhost:" + testPort
+)
+
+func TestToolboxE2E(t *testing.T) {
+	// 1. Build the binary
+	fmt.Println("--- Step 1: Building binary... ---")
+	_ = os.MkdirAll("build", 0755)
+	buildPath := "build/toolbox_test_bin"
+	buildCmd := exec.Command("go", "build", "-o", buildPath, "main.go")
+	if err := buildCmd.Run(); err != nil {
+		t.Fatalf("Failed to build binary: %v", err)
+	}
+	defer func() { _ = os.Remove(buildPath) }()
+
+	// 2. Start the server
+	fmt.Println("--- Step 2: Starting server... ---")
+	serverCmd := exec.Command("./"+buildPath, "-port", testPort)
+	if err := serverCmd.Start(); err != nil {
+		t.Fatalf("Failed to start server: %v", err)
+	}
+	defer func() {
+		if serverCmd.Process != nil {
+			_ = serverCmd.Process.Kill()
+		}
+	}()
+
+	// 3. Wait for server to be ready
+	fmt.Println("--- Step 3: Waiting for server readiness... ---")
+	ready := false
+	for i := 0; i < 10; i++ {
+		resp, err := http.Get(baseURL + "/api/tools")
+		if err == nil && resp.StatusCode == http.StatusOK {
+			ready = true
+			_ = resp.Body.Close()
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if !ready {
+		t.Fatal("Server failed to become ready in time")
+	}
+
+	// 4. Test endpoints
+	fmt.Println("--- Step 4: Testing tool endpoints... ---")
+
+	testOutputDir, err := os.MkdirTemp("", "toolbox_test_output_*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	fmt.Printf("--- Test Artifacts will be saved to: %s ---\n", testOutputDir)
+
+	tests := []struct {
+		name     string
+		path     string
+		method   string
+		fileName string
+		body     interface{}
+	}{
+		{
+			name:     "Zitie Teaching",
+			path:     "/api/zitie/teaching",
+			method:   "POST",
+			fileName: "zitie_teaching.pdf",
+			body:     map[string]string{"chars": "永和九年", "paper_size": "A4"},
+		},
+		{
+			name:     "Zitie Step",
+			path:     "/api/zitie/step",
+			method:   "POST",
+			fileName: "zitie_step.pdf",
+			body:     map[string]string{"chars": "永", "paper_size": "A4"},
+		},
+		{
+			name:     "Zitie Manuscript",
+			path:     "/api/zitie/manuscript",
+			method:   "POST",
+			fileName: "zitie_manuscript.pdf",
+			body:     map[string]string{"chars": "天道酬勤", "paper_size": "A4", "font_type": "kaiti"},
+		},
+		{
+			name:     "Learn Number Counting",
+			path:     "/api/learn-number/counting",
+			method:   "POST",
+			fileName: "counting.pdf",
+			body:     map[string]interface{}{"page_count": 1, "paper_size": "A4"},
+		},
+		{
+			name:     "Learn Number Writing",
+			path:     "/api/learn-number/writing",
+			method:   "POST",
+			fileName: "writing.pdf",
+			body:     map[string]interface{}{"start_num": 1, "end_num": 5, "paper_size": "A4"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var resp *http.Response
+			var err error
+
+			if tt.method == "POST" {
+				b, _ := json.Marshal(tt.body)
+				resp, err = http.Post(baseURL+tt.path, "application/json", bytes.NewBuffer(b))
+			} else {
+				resp, err = http.Get(baseURL + tt.path)
+			}
+
+			if err != nil {
+				t.Errorf("%s failed: %v", tt.name, err)
+				return
+			}
+			defer func() { _ = resp.Body.Close() }()
+
+			if resp.StatusCode != http.StatusOK {
+				t.Errorf("%s returned status %d", tt.name, resp.StatusCode)
+				return
+			}
+
+			contentType := resp.Header.Get("Content-Type")
+			if contentType != "application/pdf" {
+				t.Errorf("%s expected application/pdf, got %s", tt.name, contentType)
+			} else {
+				// Save PDF to temp directory for human review
+				outPath := testOutputDir + "/" + tt.fileName
+				f, err := os.Create(outPath)
+				if err != nil {
+					t.Errorf("Failed to create output file: %v", err)
+					return
+				}
+				defer func() { _ = f.Close() }()
+
+				_, err = f.ReadFrom(resp.Body)
+
+				if err != nil {
+					t.Errorf("Failed to save PDF: %v", err)
+					return
+				}
+
+				fmt.Printf("[PASS] %s: Saved to %s\n", tt.name, outPath)
+			}
+		})
+	}
+
+	fmt.Printf("\n--- ALL TESTS DONE. PLEASE REVIEW PDFS IN: %s ---\n", testOutputDir)
+}