Update code references and tests: Bookmann → Bookhoard

Code changes:
- main.go: Update cache directory path
- sidecar.go: Update file extension (.bookmann.json → .bookhoard.json)
- security.go: Update CORS example URLs
- queue_test.go: Update test database name
- feed_test.go: Update test assertions
- phase1_integration_test.go: Update test email addresses
- TEST_COVERAGE.md: Update project references

Part of project rename to Bookhoard.

cmd/server/main.go

@@ -98,7 +98,7 @@ func main() {
 	queueHandler := handlers.NewQueueHandler(queries, queueProcessor)
 
 	// Create conversion service for EPUB→KEPUB conversion
-	conversionService := services.NewConversionService(queries, "/var/bookmann/cache/kepub")
+	conversionService := services.NewConversionService(queries, "/var/bookhoard/cache/kepub")
 	opdsHandler := handlers.NewOPDSHandler(queries, conversionService)
 
 	e := echo.New()

cmd/server/tests/TEST_COVERAGE.md

@@ -1,6 +1,6 @@
 # Test Coverage Report
 
-This document provides a comprehensive overview of all test scenarios covering possible failure points in the Bookmann application.
+This document provides a comprehensive overview of all test scenarios covering possible failure points in the Bookhoard application.
 
 ## Test Files
 

cmd/server/tests/phase1_integration_test.go

@@ -24,7 +24,7 @@ func TestPhase1Integration(t *testing.T) {
 	t.Run("Cleanup_ExistingTestUser", func(t *testing.T) {
 		// Try to login as the test user first
 		loginReq := map[string]interface{}{
-			"login":    "admin@bookmann.test",
+			"login":    "admin@bookhoard.test",
 			"password": "TestPassword123!@#",
 		}
 
@@ -96,7 +96,7 @@ func TestPhase1Integration(t *testing.T) {
 	// Step 1: Create first user (should be admin)
 	t.Run("Step1_CreateFirstUser", func(t *testing.T) {
 		userReq := map[string]interface{}{
-			"email":      "admin@bookmann.test",
+			"email":      "admin@bookhoard.test",
 			"username":   "admin",
 			"password":   "TestPassword123!@#",
 			"first_name": "Admin",
@@ -120,7 +120,7 @@ func TestPhase1Integration(t *testing.T) {
 		if resp.StatusCode == http.StatusConflict {
 			t.Logf("User already exists, logging in instead...")
 			loginReq := map[string]interface{}{
-				"login":    "admin@bookmann.test",
+				"login":    "admin@bookhoard.test",
 				"password": "TestPassword123!@#",
 			}
 			body, _ := json.Marshal(loginReq)
@@ -146,7 +146,7 @@ func TestPhase1Integration(t *testing.T) {
 	var adminToken string
 	t.Run("LoginAsAdmin", func(t *testing.T) {
 		loginReq := map[string]interface{}{
-			"login":    "admin@bookmann.test",
+			"login":    "admin@bookhoard.test",
 			"password": "TestPassword123!@#",
 		}