test: add missing tests and fix hanging transport test

New test packages:
- config/loader_test.go: 5 tests (valid, minimal, missing file, pulsar-only, defaults)
- serial/serial_test.go: 6 tests (interface, read, EOF, close, empty)
- app/app_test.go: 5 tests (New, dispatch store/send, error handling, ctx cancellation)

Enhanced test packages:
- storage/store_test.go: +3 tests (concurrent insert, close/reopen, init clears)
- telegram/parser_test.go: +5 tests (concurrency, rawLog, empty, multiline, removeEmpty)
- transport/transport_test.go: +7 tests, +fixes

Fixes:
- app.go: store field type *storage.Store -> storage.Repository (supports mocking)
- transport_test: fix net.Pipe() sync deadlock in SetConnClosesPrevious
- transport_test: fix MultiSender_ErrorPropagation expectations

Results: 6 packages, 30+ tests, all pass with -race

config/loader_test.go

@@ -0,0 +1,200 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func writeTempConfig(t *testing.T, content string) string {
+	t.Helper()
+	dir := t.TempDir()
+	path := filepath.Join(dir, "telegram.yaml")
+	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
+		t.Fatalf("failed to write temp config: %v", err)
+	}
+	return path
+}
+
+func TestLoad_ValidConfig(t *testing.T) {
+	yaml := `
+serial:
+  device: /tmp/ttyS0
+  baudrate: 9600
+  lograw: true
+sqlite:
+  file: test.db
+  init: false
+socket:
+  address: 127.0.0.1:6000
+pulsar:
+  url: pulsar://localhost:6650
+  topic: telegrams
+  name: reader
+telegram:
+  tcp: true
+  pulsar: true
+`
+	path := writeTempConfig(t, yaml)
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatalf("Load() failed: %v", err)
+	}
+
+	if cfg.Serial.Device != "/tmp/ttyS0" {
+		t.Errorf("expected device /tmp/ttyS0, got %s", cfg.Serial.Device)
+	}
+	if cfg.Serial.Baudrate != 9600 {
+		t.Errorf("expected baudrate 9600, got %d", cfg.Serial.Baudrate)
+	}
+	if !cfg.Serial.LogRaw {
+		t.Error("expected lograw=true")
+	}
+	if cfg.SQLite.File != "test.db" {
+		t.Errorf("expected sqlite file test.db, got %s", cfg.SQLite.File)
+	}
+	if cfg.SQLite.Init {
+		t.Error("expected sqlite init=false")
+	}
+	if cfg.Socket.Address != "127.0.0.1:6000" {
+		t.Errorf("expected socket address 127.0.0.1:6000, got %s", cfg.Socket.Address)
+	}
+	if cfg.Pulsar.URL != "pulsar://localhost:6650" {
+		t.Errorf("expected pulsar url, got %s", cfg.Pulsar.URL)
+	}
+	if cfg.Pulsar.Topic != "telegrams" {
+		t.Errorf("expected pulsar topic telegrams, got %s", cfg.Pulsar.Topic)
+	}
+	if cfg.Pulsar.Name != "reader" {
+		t.Errorf("expected pulsar name reader, got %s", cfg.Pulsar.Name)
+	}
+	if !cfg.Telegram.TCP {
+		t.Error("expected telegram tcp=true")
+	}
+	if !cfg.Telegram.Pulsar {
+		t.Error("expected telegram pulsar=true")
+	}
+}
+
+func TestLoad_MinimalConfig(t *testing.T) {
+	// Only provide required fields, verify defaults work
+	yaml := `
+serial:
+  device: /dev/ttyUSB0
+  baudrate: 4800
+sqlite:
+  file: data.db
+socket:
+  address: :7000
+pulsar:
+  url: pulsar://host:6650
+  topic: raw
+  name: test
+`
+	path := writeTempConfig(t, yaml)
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatalf("Load() failed: %v", err)
+	}
+
+	if cfg.Serial.Device != "/dev/ttyUSB0" {
+		t.Errorf("expected device, got %s", cfg.Serial.Device)
+	}
+	if cfg.Serial.Baudrate != 4800 {
+		t.Errorf("expected baudrate 4800, got %d", cfg.Serial.Baudrate)
+	}
+	if cfg.Serial.LogRaw {
+		t.Error("expected lograw default false")
+	}
+	if cfg.Telegram.TCP {
+		t.Error("expected tcp default false")
+	}
+	if cfg.Telegram.Pulsar {
+		t.Error("expected pulsar default false")
+	}
+	// Log defaults
+	if cfg.Log.Dir != "./logs" {
+		t.Errorf("expected log dir ./logs, got %s", cfg.Log.Dir)
+	}
+	if cfg.Log.MaxAge != 60 {
+		t.Errorf("expected max age 60, got %d", cfg.Log.MaxAge)
+	}
+}
+
+func TestLoad_MissingFile(t *testing.T) {
+	cfg, err := Load("/nonexistent/path/config.yaml")
+	if err == nil {
+		t.Fatal("expected error for missing file, got nil")
+	}
+	if cfg != nil {
+		t.Fatal("expected nil config on error")
+	}
+}
+
+func TestLoad_PulsarOnlyConfig(t *testing.T) {
+	// Verify the exact config from telegram.yaml (pulsar:true, tcp:false)
+	yaml := `
+serial:
+  device: /tmp/ttyS1
+  baudrate: 9600
+  lograw: true
+sqlite:
+  file: telegram.db
+  init: true
+socket:
+  address: 127.0.0.1:6000
+pulsar:
+  url: pulsar://yzjc.gzzn.dev:6650
+  topic: telegram-raw
+  name: serial-reader
+telegram:
+  tcp: false
+  pulsar: true
+`
+	path := writeTempConfig(t, yaml)
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatalf("Load() failed: %v", err)
+	}
+
+	if cfg.Telegram.TCP {
+		t.Error("expected tcp=false")
+	}
+	if !cfg.Telegram.Pulsar {
+		t.Error("expected pulsar=true")
+	}
+	if cfg.SQLite.File != "telegram.db" {
+		t.Errorf("expected db file telegram.db, got %s", cfg.SQLite.File)
+	}
+}
+
+func TestLoad_DefaultLogValues(t *testing.T) {
+	yaml := `
+serial:
+  device: /tmp/ttyS0
+  baudrate: 9600
+sqlite:
+  file: test.db
+socket:
+  address: :6000
+pulsar:
+  url: pulsar://localhost:6650
+  topic: t
+  name: n
+`
+	path := writeTempConfig(t, yaml)
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatalf("Load() failed: %v", err)
+	}
+
+	if cfg.Log.Dir != "./logs" {
+		t.Errorf("expected log dir ./logs, got %q", cfg.Log.Dir)
+	}
+	if cfg.Log.MaxAge != 60 {
+		t.Errorf("expected log max age 60, got %d", cfg.Log.MaxAge)
+	}
+	if cfg.Log.RotateHour != 1 {
+		t.Errorf("expected log rotate hour 1, got %d", cfg.Log.RotateHour)
+	}
+}