chore(router): remove unused CollectionHandler from config

Remove the CollectionHandler field from router.Config struct and its
initialization in main.go. This field was never used - collections are
registered directly in handlers.SetupRoutes() where a CollectionHandler
is created locally.

Changes:
- Remove CollectionHandler field from internal/router/router.go Config
- Remove CollectionHandler: nil line from cmd/server/main.go

This cleans up dead code from the router refactoring. Collections
continue to work correctly as they are registered in SetupRoutes().

Related: Router refactoring completion

internal/app/app_test.go

@@ -0,0 +1,373 @@
+package app
+
+import (
+	"context"
+	"os"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/labstack/echo/v4"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// mockHandler is a mock implementation of the Handler interface for testing
+type mockHandler struct {
+	startSchedulerCalled bool
+	stopSchedulerCalled  bool
+	startDelay           time.Duration
+	stopDelay            time.Duration
+	startError           error
+	stopError            error
+}
+
+func (m *mockHandler) StartScheduler() {
+	m.startSchedulerCalled = true
+	if m.startDelay > 0 {
+		time.Sleep(m.startDelay)
+	}
+	if m.startError != nil {
+		panic(m.startError)
+	}
+}
+
+func (m *mockHandler) StopScheduler() {
+	m.stopSchedulerCalled = true
+	if m.stopDelay > 0 {
+		time.Sleep(m.stopDelay)
+	}
+	if m.stopError != nil {
+		panic(m.stopError)
+	}
+}
+
+// reset resets the mock handler state
+func (m *mockHandler) reset() {
+	m.startSchedulerCalled = false
+	m.stopSchedulerCalled = false
+}
+
+// TestApp_New tests Phase 5: App constructor
+func TestApp_New(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{}
+
+	app := New(e, handler)
+
+	assert.NotNil(t, app, "App should not be nil")
+	assert.Equal(t, e, app.echo, "Echo instance should be stored")
+	assert.Equal(t, handler, app.handler, "Handler should be stored")
+	assert.Equal(t, 30*time.Second, app.shutdownTimeout, "Default shutdown timeout should be 30 seconds")
+	assert.NotNil(t, app.shutdownDone, "Shutdown done channel should be initialized")
+}
+
+// TestApp_SetShutdownTimeout tests Phase 5: configurable shutdown timeout
+func TestApp_SetShutdownTimeout(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{}
+	app := New(e, handler)
+
+	customTimeout := 15 * time.Second
+	app.SetShutdownTimeout(customTimeout)
+
+	assert.Equal(t, customTimeout, app.shutdownTimeout, "Shutdown timeout should be updated")
+}
+
+// TestApp_ShutdownDone tests Phase 5: shutdown done channel
+func TestApp_ShutdownDone(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{}
+	app := New(e, handler)
+
+	channel := app.ShutdownDone()
+	assert.NotNil(t, channel, "ShutdownDone should return a channel")
+	// Verify it's the same channel by checking if it's readable
+	select {
+	case <-channel:
+		// Channel should not be closed yet
+		t.Error("ShutdownDone channel should not be closed immediately")
+	default:
+		// Expected - channel is open but not ready
+	}
+}
+
+// TestApp_Start_BackgroundServices tests Phase 1 & 5: background service startup
+func TestApp_Start_BackgroundServices(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{
+		startDelay: 100 * time.Millisecond, // Short delay to verify async startup
+	}
+	app := New(e, handler)
+
+	// Start the app in a goroutine (simulating main.go)
+	done := make(chan error, 1)
+	go func() {
+		// This will block until shutdown signal
+		err := app.Start()
+		done <- err
+	}()
+
+	// Wait a bit for background services to start
+	time.Sleep(150 * time.Millisecond)
+
+	// Verify scheduler was started
+	assert.True(t, handler.startSchedulerCalled, "StartScheduler should be called")
+
+	// Send shutdown signal to clean up
+	done2 := make(chan bool)
+	go func() {
+		// Send shutdown signal
+		process, err := os.FindProcess(os.Getpid())
+		require.NoError(t, err, "Should find current process")
+		err = process.Signal(syscall.SIGTERM)
+		done2 <- (err == nil)
+	}()
+
+	// Wait for app to finish
+	select {
+	case err := <-done:
+		assert.NoError(t, err, "App should shut down without error")
+	case <-time.After(5 * time.Second):
+		t.Fatal("App did not shut down within timeout")
+	}
+
+	<-done2
+}
+
+// TestApp_Shutdown_GracefulShutdown tests Phase 5: graceful shutdown sequence
+func TestApp_Shutdown_GracefulShutdown(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{
+		stopDelay: 50 * time.Millisecond,
+	}
+	app := New(e, handler)
+
+	// Test shutdown
+	err := app.Shutdown()
+
+	assert.NoError(t, err, "Shutdown should complete without error")
+	assert.True(t, handler.stopSchedulerCalled, "StopScheduler should be called")
+}
+
+// TestApp_Shutdown_ThreadSafety tests Phase 5: thread-safe shutdown
+func TestApp_Shutdown_ThreadSafety(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{}
+	app := New(e, handler)
+
+	// Call shutdown multiple times concurrently
+	errors := make(chan error, 3)
+	for i := 0; i < 3; i++ {
+		go func() {
+			errors <- app.Shutdown()
+		}()
+	}
+
+	// Collect results
+	for i := 0; i < 3; i++ {
+		err := <-errors
+		// First call should succeed, subsequent calls should also succeed (no-op)
+		assert.NoError(t, err, "Concurrent shutdown calls should not error")
+	}
+
+	// Verify handler was stopped only once
+	assert.True(t, handler.stopSchedulerCalled, "StopScheduler should be called at least once")
+}
+
+// TestApp_Shutdown_Timeout tests Phase 5: shutdown timeout handling
+func TestApp_Shutdown_Timeout(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{
+		stopDelay: 2 * time.Second, // Longer than shutdown timeout
+	}
+	app := New(e, handler)
+	app.SetShutdownTimeout(100 * time.Millisecond) // Set very short timeout
+
+	// Test shutdown with timeout
+	err := app.Shutdown()
+
+	assert.Error(t, err, "Shutdown should timeout and return error")
+	assert.True(t, handler.stopSchedulerCalled, "StopScheduler should still be called")
+}
+
+// TestApp_Shutdown_ClosesEchoServer tests Phase 5: HTTP server shutdown
+func TestApp_Shutdown_ClosesEchoServer(t *testing.T) {
+	e := echo.New()
+	handler := &mockHandler{}
+
+	// Start a simple server
+	go func() {
+		e.Start(":0") // Use random port
+	}()
+
+	// Give server time to start
+	time.Sleep(100 * time.Millisecond)
+
+	app := New(e, handler)
+
+	// Shutdown should close the echo server
+	err := app.Shutdown()
+
+	assert.NoError(t, err, "Shutdown should complete")
+	assert.True(t, handler.stopSchedulerCalled, "StopScheduler should be called")
+}
+
+// TestApp_SignalHandling tests Phase 5: signal handling (SIGINT, SIGTERM, SIGQUIT)
+func TestApp_SignalHandling(t *testing.T) {
+	tests := []struct {
+		name   string
+		signal os.Signal
+	}{
+		{"SIGINT", syscall.SIGINT},
+		{"SIGTERM", syscall.SIGTERM},
+		{"SIGQUIT", syscall.SIGQUIT},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := echo.New()
+			handler := &mockHandler{}
+			app := New(e, handler)
+
+			// Start app in goroutine
+			done := make(chan error, 1)
+			go func() {
+				done <- app.Start()
+			}()
+
+			// Wait for background services to start
+			time.Sleep(100 * time.Millisecond)
+			assert.True(t, handler.startSchedulerCalled, "StartScheduler should be called")
+
+			// Send signal
+			process, err := os.FindProcess(os.Getpid())
+			require.NoError(t, err, "Should find current process")
+
+			err = process.Signal(tt.signal)
+			require.NoError(t, err, "Should send signal")
+
+			// Wait for shutdown
+			select {
+			case err := <-done:
+				assert.NoError(t, err, "App should shut down without error")
+				assert.True(t, handler.stopSchedulerCalled, "StopScheduler should be called")
+			case <-time.After(5 * time.Second):
+				t.Fatal("App did not shut down within timeout")
+			}
+		})
+	}
+}
+
+// TestApp_Integration_StartupSequence tests Phase 1 & 5: complete startup sequence
+func TestApp_Integration_StartupSequence(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	e := echo.New()
+	handler := &mockHandler{}
+	app := New(e, handler)
+
+	// This test simulates the sequence in cmd/server/main.go:
+	// 1. Create app
+	// 2. Start HTTP server in background
+	// 3. Call app.Start() which blocks until signal
+
+	// Step 1: App already created above
+	assert.NotNil(t, app, "App should be created")
+
+	// Step 2: Start HTTP server (simulated)
+	serverReady := make(chan bool)
+	go func() {
+		// In real main.go, this would be: e.Start(":" + cfg.ServerPort)
+		// For testing, we don't actually start the server
+		serverReady <- true
+		<-context.Background().Done() // Block until done
+	}()
+
+	<-serverReady
+
+	// Step 3: Start app lifecycle in background
+	appDone := make(chan error, 1)
+	go func() {
+		appDone <- app.Start()
+	}()
+
+	// Verify background services started
+	time.Sleep(150 * time.Millisecond)
+	assert.True(t, handler.startSchedulerCalled, "Scheduler should be started")
+
+	// Send shutdown signal (simulating user pressing Ctrl+C)
+	process, err := os.FindProcess(os.Getpid())
+	require.NoError(t, err)
+	err = process.Signal(syscall.SIGINT)
+	require.NoError(t, err)
+
+	// Wait for graceful shutdown
+	select {
+	case err := <-appDone:
+		assert.NoError(t, err, "App should shut down gracefully")
+		assert.True(t, handler.stopSchedulerCalled, "Scheduler should be stopped")
+	case <-time.After(5 * time.Second):
+		t.Fatal("App did not complete shutdown within timeout")
+	}
+}
+
+// TestApp_HandlerInterface tests that Handler interface is properly implemented
+func TestApp_HandlerInterface(t *testing.T) {
+	// This test verifies that the mock handler satisfies the Handler interface
+	var _ Handler = &mockHandler{}
+}
+
+// TestPhase1_AutoStartVerification tests Phase 1: auto-start functionality
+func TestPhase1_AutoStartVerification(t *testing.T) {
+	t.Run("Auto-start runs asynchronously", func(t *testing.T) {
+		e := echo.New()
+		handler := &mockHandler{
+			startDelay: 100 * time.Millisecond,
+		}
+		app := New(e, handler)
+
+		// Start the app - it should start background services and return immediately
+		// Then we send a shutdown signal right away
+		done := make(chan error, 1)
+		go func() {
+			// This will start services in background, then wait for signal
+			err := app.Start()
+			done <- err
+		}()
+
+		// Wait a bit for background services to start
+		time.Sleep(150 * time.Millisecond)
+
+		// Verify scheduler was started in background
+		assert.True(t, handler.startSchedulerCalled, "StartScheduler should be called in background")
+
+		// Send shutdown signal
+		process, err := os.FindProcess(os.Getpid())
+		require.NoError(t, err)
+		_ = process.Signal(syscall.SIGTERM)
+
+		// Wait for clean shutdown
+		select {
+		case err := <-done:
+			assert.NoError(t, err, "App should shut down gracefully")
+		case <-time.After(5 * time.Second):
+			t.Fatal("App did not shut down within timeout")
+		}
+	})
+}
+
+// BenchmarkApp_Shutdown benchmarks the shutdown process
+func BenchmarkApp_Shutdown(b *testing.B) {
+	e := echo.New()
+	handler := &mockHandler{}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		handler.reset()
+		app := New(e, handler)
+		app.Shutdown()
+	}
+}

internal/router/router.go

@@ -43,7 +43,6 @@ type Config struct {
 	ConflictHandler      *handlers.ConflictHandler
 	AnalyticsHandler     *handlers.AnalyticsHandler
 	QueueHandler         *handlers.QueueHandler
-	CollectionHandler    *handlers.CollectionHandler
 	OPDSHandler          *handlers.OPDSHandler
 	ConnManager          *sync.ConnectionManager
 	QueueProcessor       *sync.SyncQueueProcessor

internal/services/ebook_scanner_library_type_test.go

@@ -0,0 +1,253 @@
+package services
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestEbookScanner_LibraryTypeAwareScanning tests Phase 2: library-type-aware scanning
+func TestEbookScanner_LibraryTypeAwareScanning(t *testing.T) {
+	t.Run("isScannableFile checks library type restrictions", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders: []string{"/test/ebooks", "/test/comics"},
+			libraryTypes: map[string][]string{
+				"/test/ebooks": {".epub", ".mobi", ".azw3"},
+				"/test/comics": {".cbz", ".cbr", ".cb7", ".cbt"},
+			},
+		}
+
+		tests := []struct {
+			name     string
+			filePath string
+			expected bool
+		}{
+			{
+				name:     "EPUB in ebooks folder",
+				filePath: "/test/ebooks/book.epub",
+				expected: true,
+			},
+			{
+				name:     "MOBI in ebooks folder",
+				filePath: "/test/ebooks/book.mobi",
+				expected: true,
+			},
+			{
+				name:     "CBZ in ebooks folder (should be rejected)",
+				filePath: "/test/ebooks/comic.cbz",
+				expected: false,
+			},
+			{
+				name:     "CBZ in comics folder",
+				filePath: "/test/comics/issue.cbz",
+				expected: true,
+			},
+			{
+				name:     "CBR in comics folder",
+				filePath: "/test/comics/issue.cbr",
+				expected: true,
+			},
+			{
+				name:     "EPUB in comics folder (should be rejected)",
+				filePath: "/test/comics/book.epub",
+				expected: false,
+			},
+			{
+				name:     "File outside watched folders",
+				filePath: "/other/path/file.epub",
+				expected: false,
+			},
+			{
+				name:     "Unknown extension in ebooks folder",
+				filePath: "/test/ebooks/file.pdf",
+				expected: false,
+			},
+		}
+
+		for _, tt := range tests {
+			t.Run(tt.name, func(t *testing.T) {
+				result := scanner.isScannableFile(tt.filePath)
+				assert.Equal(t, tt.expected, result, "isScannableFile(%s) should return %v", tt.filePath, tt.expected)
+			})
+		}
+	})
+
+	t.Run("isScannableFile case insensitive", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders: []string{"/test/ebooks"},
+			libraryTypes: map[string][]string{
+				"/test/ebooks": {".epub"},
+			},
+		}
+
+		tests := []struct {
+			name     string
+			filePath string
+			expected bool
+		}{
+			{"Lowercase extension", "/test/ebooks/book.epub", true},
+			{"Uppercase extension", "/test/ebooks/book.EPUB", true},
+			{"Mixed case extension", "/test/ebooks/book.Epub", true},
+		}
+
+		for _, tt := range tests {
+			t.Run(tt.name, func(t *testing.T) {
+				result := scanner.isScannableFile(tt.filePath)
+				assert.Equal(t, tt.expected, result)
+			})
+		}
+	})
+
+	t.Run("isScannableFile with no library type info", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders:      []string{"/test/ebooks"},
+			libraryTypes: map[string][]string{}, // Empty library types
+		}
+
+		result := scanner.isScannableFile("/test/ebooks/book.epub")
+		assert.False(t, result, "Should reject files when library type info is missing")
+	})
+
+	t.Run("isScannableFile handles subdirectories", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders: []string{"/test/ebooks"},
+			libraryTypes: map[string][]string{
+				"/test/ebooks": {".epub"},
+			},
+		}
+
+		result := scanner.isScannableFile("/test/ebooks/subdir/book.epub")
+		assert.True(t, result, "Should accept files in subdirectories")
+	})
+}
+
+// TestEbookScanner_SetFolders_BuildsLibraryTypeCache tests Phase 2: SetFolders builds cache
+func TestEbookScanner_SetFolders_BuildsLibraryTypeCache(t *testing.T) {
+	// This is a unit test that verifies SetFolders properly initializes the libraryTypes cache
+	// Full integration testing would require a mock database
+
+	t.Run("SetFolders initializes libraryTypes map", func(t *testing.T) {
+		scanner := &EbookScanner{
+			libraryTypes: nil,
+		}
+
+		// Simulate SetFolders initialization
+		scanner.libraryTypes = make(map[string][]string)
+		assert.NotNil(t, scanner.libraryTypes, "libraryTypes should be initialized")
+		assert.Equal(t, 0, len(scanner.libraryTypes), "libraryTypes should be empty initially")
+	})
+
+	t.Run("SetFolders clears old library types", func(t *testing.T) {
+		scanner := &EbookScanner{
+			libraryTypes: map[string][]string{
+				"/old/folder": {".epub"},
+			},
+		}
+
+		// Simulate SetFolders clearing and rebuilding
+		scanner.libraryTypes = make(map[string][]string)
+		assert.Equal(t, 0, len(scanner.libraryTypes), "Old library types should be cleared")
+	})
+}
+
+// TestEbookScanner_LibraryTypeCrossContamination tests Phase 2: prevents cross-contamination
+func TestEbookScanner_LibraryTypeCrossContamination(t *testing.T) {
+	t.Run("Ebook library rejects comic formats", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders: []string{"/library/ebooks"},
+			libraryTypes: map[string][]string{
+				"/library/ebooks": {".epub", ".mobi", ".azw3", ".pdf"},
+			},
+		}
+
+		comicFormats := []string{".cbz", ".cbr", ".cb7", ".cbt"}
+		for _, ext := range comicFormats {
+			filePath := "/library/ebooks/comic" + ext
+			result := scanner.isScannableFile(filePath)
+			assert.False(t, result, "Ebook library should reject %s files", ext)
+		}
+	})
+
+	t.Run("Comic library rejects ebook formats", func(t *testing.T) {
+		scanner := &EbookScanner{
+			folders: []string{"/library/comics"},
+			libraryTypes: map[string][]string{
+				"/library/comics": {".cbz", ".cbr", ".cb7", ".cbt"},
+			},
+		}
+
+		ebookFormats := []string{".epub", ".mobi", ".azw3", ".pdf", ".djvu"}
+		for _, ext := range ebookFormats {
+			filePath := "/library/comics/book" + ext
+			result := scanner.isScannableFile(filePath)
+			assert.False(t, result, "Comic library should reject %s files", ext)
+		}
+	})
+}
+
+// TestEbookScanner_MultipleLibraryTypes tests Phase 2: multiple libraries with different types
+func TestEbookScanner_MultipleLibraryTypes(t *testing.T) {
+	scanner := &EbookScanner{
+		folders: []string{
+			"/library/ebooks",
+			"/library/comics",
+			"/library/manga",
+		},
+		libraryTypes: map[string][]string{
+			"/library/ebooks": {".epub", ".mobi", ".azw3"},
+			"/library/comics": {".cbz", ".cbr"},
+			"/library/manga":  {".cbz", ".cb7"}, // Manga uses CBZ and CB7
+		},
+	}
+
+	tests := []struct {
+		name     string
+		filePath string
+		expected bool
+		reason   string
+	}{
+		{
+			name:     "EPUB in ebook library",
+			filePath: "/library/ebooks/novel.epub",
+			expected: true,
+			reason:   "EPUB allowed in ebook library",
+		},
+		{
+			name:     "CBZ in comic library",
+			filePath: "/library/comics/superman.cbz",
+			expected: true,
+			reason:   "CBZ allowed in comic library",
+		},
+		{
+			name:     "CBZ in manga library",
+			filePath: "/library/manga/naruto.cbz",
+			expected: true,
+			reason:   "CBZ allowed in manga library",
+		},
+		{
+			name:     "CB7 in manga library",
+			filePath: "/library/manga/onepiece.cb7",
+			expected: true,
+			reason:   "CB7 allowed in manga library",
+		},
+		{
+			name:     "CB7 in comic library (rejected)",
+			filePath: "/library/comics/batman.cb7",
+			expected: false,
+			reason:   "CB7 not allowed in comic library",
+		},
+		{
+			name:     "EPUB in comic library (rejected)",
+			filePath: "/library/comics/novel.epub",
+			expected: false,
+			reason:   "EPUB not allowed in comic library",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := scanner.isScannableFile(tt.filePath)
+			assert.Equal(t, tt.expected, result, tt.reason)
+		})
+	}
+}