Add initial project structure with core functionality for book and stationery uploads

- Created main application entry point in `main.go`.
- Added configuration management in `config/config.go` and tests in `config/config_test.go`.
- Implemented handlers for book and stationery uploads in `handlers/book.go` and `handlers/stationery.go`, including validation logic.
- Established database connection and services in `services/database.go` and `services/book_service.go`.
- Defined models for books and stationery in `models/book.go` and `models/stationery.go`.
- Set up Firebase integration for image uploads in `services/firebase.go`.
- Created migration scripts for database schema in `migrations/001_create_tables.sql` and subsequent updates.
- Added CORS and error handling middleware.
- Included comprehensive tests for handlers, services, and utilities.
- Documented API endpoints and usage in `README.md` and migration instructions in `migrations/README.md`.
- Introduced `.gitignore` to exclude unnecessary files and directories.
- Added Go module support with `go.mod` and `go.sum` files.
- Implemented utility functions for slug generation and validation in `utils/slug.go` and `utils/validation.go`.

utils/slug_test.go

@@ -0,0 +1,177 @@
+package utils
+
+import "testing"
+
+func TestGenerateSlug(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "simple text",
+			input:    "Hello World",
+			expected: "hello-world",
+		},
+		{
+			name:     "text with special characters",
+			input:    "Book Name!@#$%",
+			expected: "book-name",
+		},
+		{
+			name:     "text with numbers",
+			input:    "Book 123",
+			expected: "book-123",
+		},
+		{
+			name:     "text with multiple spaces",
+			input:    "Book   Name   Here",
+			expected: "book-name-here",
+		},
+		{
+			name:     "text with underscores",
+			input:    "Book_Name_Here",
+			expected: "book-name-here",
+		},
+		{
+			name:     "text with mixed case",
+			input:    "My Awesome Book",
+			expected: "my-awesome-book",
+		},
+		{
+			name:     "empty string",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "only special characters",
+			input:    "!@#$%",
+			expected: "item",
+		},
+		{
+			name:     "leading and trailing spaces",
+			input:    "  Book Name  ",
+			expected: "book-name",
+		},
+		{
+			name:     "text with hyphens",
+			input:    "Book-Name-Here",
+			expected: "book-name-here",
+		},
+		{
+			name:     "text with consecutive special chars",
+			input:    "Book!!!Name",
+			expected: "bookname",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := GenerateSlug(tt.input)
+			if result != tt.expected {
+				t.Errorf("GenerateSlug(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestIsValidSlug(t *testing.T) {
+	tests := []struct {
+		name     string
+		slug     string
+		expected bool
+	}{
+		{
+			name:     "valid slug",
+			slug:     "hello-world",
+			expected: true,
+		},
+		{
+			name:     "valid slug with numbers",
+			slug:     "book-123",
+			expected: true,
+		},
+		{
+			name:     "invalid - uppercase",
+			slug:     "Hello-World",
+			expected: false,
+		},
+		{
+			name:     "invalid - special characters",
+			slug:     "hello-world!",
+			expected: false,
+		},
+		{
+			name:     "invalid - leading hyphen",
+			slug:     "-hello-world",
+			expected: false,
+		},
+		{
+			name:     "invalid - trailing hyphen",
+			slug:     "hello-world-",
+			expected: false,
+		},
+		{
+			name:     "invalid - consecutive hyphens",
+			slug:     "hello--world",
+			expected: false,
+		},
+		{
+			name:     "invalid - empty",
+			slug:     "",
+			expected: false,
+		},
+		{
+			name:     "valid - single word",
+			slug:     "book",
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := IsValidSlug(tt.slug)
+			if result != tt.expected {
+				t.Errorf("IsValidSlug(%q) = %v, want %v", tt.slug, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestCleanString(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "normal string",
+			input:    "Hello World",
+			expected: "Hello World",
+		},
+		{
+			name:     "with leading/trailing spaces",
+			input:    "  Hello World  ",
+			expected: "Hello World",
+		},
+		{
+			name:     "with multiple spaces",
+			input:    "Hello    World",
+			expected: "Hello World",
+		},
+		{
+			name:     "empty string",
+			input:    "",
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := CleanString(tt.input)
+			if result != tt.expected {
+				t.Errorf("CleanString(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}