Coverage priorities 1-5: test pure functions, extract interfaces, mock-based handler tests

- Priority 1: Test NewSendEmailTask + NewSendPushTask (5 tests)
- Priority 2: Test customHTTPErrorHandler — all 15+ branches (21 tests)
- Priority 3: Extract Enqueuer interface + payload builders in worker pkg (5 tests)
- Priority 4: Extract ClassifyFile/ComputeRelPath in migrate-encrypt (6 tests)
- Priority 5: Define Handler interfaces, refactor to accept them, mock-based tests (14 tests)
- Fix .gitignore: /worker instead of worker to stop ignoring internal/worker/

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/database/database_test.go

@@ -0,0 +1,103 @@
+package database
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+// --- Unit tests for Paginate parameter clamping ---
+
+func TestPaginate_PageZeroDefaultsToOne(t *testing.T) {
+	scope := Paginate(0, 10)
+
+	db := openTestDB(t)
+	createTestRows(t, db, 5)
+
+	var rows []testRow
+	err := db.Scopes(scope).Find(&rows).Error
+	require.NoError(t, err)
+	// page=0 normalised to page=1, pageSize=10 → should get all 5 rows
+	assert.Len(t, rows, 5)
+}
+
+func TestPaginate_PageSizeZeroDefaultsTo100(t *testing.T) {
+	scope := Paginate(1, 0)
+
+	db := openTestDB(t)
+	createTestRows(t, db, 5)
+
+	var rows []testRow
+	err := db.Scopes(scope).Find(&rows).Error
+	require.NoError(t, err)
+	// pageSize=0 normalised to 100, only 5 rows exist → 5 returned
+	assert.Len(t, rows, 5)
+}
+
+func TestPaginate_PageSizeOverMaxCappedAt1000(t *testing.T) {
+	scope := Paginate(1, 2000)
+
+	db := openTestDB(t)
+	createTestRows(t, db, 5)
+
+	var rows []testRow
+	err := db.Scopes(scope).Find(&rows).Error
+	require.NoError(t, err)
+	// pageSize=2000 capped to 1000, only 5 rows → 5 returned
+	assert.Len(t, rows, 5)
+}
+
+func TestPaginate_NormalValues(t *testing.T) {
+	scope := Paginate(1, 3)
+
+	db := openTestDB(t)
+	createTestRows(t, db, 10)
+
+	var rows []testRow
+	err := db.Scopes(scope).Order("id ASC").Find(&rows).Error
+	require.NoError(t, err)
+	assert.Len(t, rows, 3)
+	assert.Equal(t, "row_1", rows[0].Name)
+	assert.Equal(t, "row_3", rows[2].Name)
+}
+
+func TestPaginate_SQLiteIntegration_Page2Size10(t *testing.T) {
+	db := openTestDB(t)
+	createTestRows(t, db, 25)
+
+	scope := Paginate(2, 10)
+	var rows []testRow
+	err := db.Scopes(scope).Order("id ASC").Find(&rows).Error
+	require.NoError(t, err)
+
+	// Page 2 with size 10 → rows 11..20
+	assert.Len(t, rows, 10)
+	assert.Equal(t, "row_11", rows[0].Name)
+	assert.Equal(t, "row_20", rows[9].Name)
+}
+
+// --- helpers ---
+
+type testRow struct {
+	ID   uint   `gorm:"primaryKey"`
+	Name string
+}
+
+func openTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	require.NoError(t, err)
+	require.NoError(t, db.AutoMigrate(&testRow{}))
+	return db
+}
+
+func createTestRows(t *testing.T, db *gorm.DB, n int) {
+	t.Helper()
+	for i := 1; i <= n; i++ {
+		require.NoError(t, db.Create(&testRow{Name: fmt.Sprintf("row_%d", i)}).Error)
+	}
+}