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/echohelpers/helpers_test.go

@@ -0,0 +1,105 @@
+package echohelpers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/labstack/echo/v4"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefaultQuery(t *testing.T) {
+	tests := []struct {
+		name         string
+		query        string
+		key          string
+		defaultValue string
+		expected     string
+	}{
+		{"returns value when present", "/?status=active", "status", "all", "active"},
+		{"returns default when absent", "/", "status", "all", "all"},
+		{"returns default for empty value", "/?status=", "status", "all", "all"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			e := echo.New()
+			req := httptest.NewRequest(http.MethodGet, tc.query, nil)
+			rec := httptest.NewRecorder()
+			c := e.NewContext(req, rec)
+
+			result := DefaultQuery(c, tc.key, tc.defaultValue)
+			assert.Equal(t, tc.expected, result)
+		})
+	}
+}
+
+func TestParseUintParam(t *testing.T) {
+	tests := []struct {
+		name        string
+		paramValue  string
+		expected    uint
+		expectError bool
+	}{
+		{"valid uint", "42", 42, false},
+		{"zero", "0", 0, false},
+		{"invalid string", "abc", 0, true},
+		{"negative", "-1", 0, true},
+		{"empty", "", 0, true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			e := echo.New()
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			rec := httptest.NewRecorder()
+			c := e.NewContext(req, rec)
+			c.SetParamNames("id")
+			c.SetParamValues(tc.paramValue)
+
+			result, err := ParseUintParam(c, "id")
+			if tc.expectError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				assert.Equal(t, tc.expected, result)
+			}
+		})
+	}
+}
+
+func TestParseIntParam(t *testing.T) {
+	tests := []struct {
+		name        string
+		paramValue  string
+		expected    int
+		expectError bool
+	}{
+		{"valid int", "42", 42, false},
+		{"zero", "0", 0, false},
+		{"negative", "-5", -5, false},
+		{"invalid string", "abc", 0, true},
+		{"empty", "", 0, true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			e := echo.New()
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			rec := httptest.NewRecorder()
+			c := e.NewContext(req, rec)
+			c.SetParamNames("id")
+			c.SetParamValues(tc.paramValue)
+
+			result, err := ParseIntParam(c, "id")
+			if tc.expectError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				assert.Equal(t, tc.expected, result)
+			}
+		})
+	}
+}