fix: comprehensive bug fixes and architecture restructuring

Phase 1 — Bug fixes (7 bugs):
- Bug 1: Pulsar mode data loss — always persist to SQLite regardless of mode
- Bug 2: PulsarSend closing TCP client — use independent resetPulsarProducer()
- Bug 3: Greedy regex — use non-greedy (?s)ZCZC.*?NNNN
- Bug 4: Data after NNNN discarded — keep remaining buffer data
- Bug 5: strings.Index > 0 boundary — use strings.Contains
- Bug 6: Variable shadowing in PulsarSend — use = not :=
- Bug 7: Accept failure nil panic — add continue + retry logic

Phase 2 — Architecture restructuring:
- Split utils/ into config/, serial/, telegram/, storage/, transport/
- Define Sender, Repository, Reader interfaces
- Introduce app/ layer with context.Context lifecycle
- Replace spinlock with sync.Mutex
- Unified Config struct replaces 15+ global vars

Phase 3 — Testing & tooling:
- telegram/parser_test.go (7 test cases)
- storage/store_test.go (5 test cases)
- transport/transport_test.go (4 test cases)
- Taskfile: add test, test-race, test-cover tasks
- Go version: 1.15 -> 1.21

utils/sqlite.go

@@ -65,30 +65,38 @@ func InitDb(file string, init bool) error {
 	return nil
 }
 
-func InsertTelegram(teleString string) {
-	if Tcp {
-		getWriteLock()
-		db := getDb()
-		defer db.Close()
-		var insertSQL string
-		if ClientReady && WriteToClient(teleString) == nil {
-			insertSQL = InsertOld
-		} else {
-			insertSQL = InsertNew
-		}
-		stmt, _ := db.Prepare(insertSQL)
-
-		defer stmt.Close()
-		result, err := stmt.Exec(teleString)
-		id, _ := result.LastInsertId()
-		checkDbErr(err, "error in insert telegram ")
-		isWriting = false
-		if insertSQL == InsertOld {
-			Log.Info("telegram processed ", zap.Int64("id", id))
-		} else {
-			Log.Info("telegram saved ", zap.Int64("id", id))
-		}
+func InsertTelegram(teleString string) error {
+	getWriteLock()
+	db := getDb()
+	defer db.Close()
+	var insertSQL string
+	if ClientReady && WriteToClient(teleString) == nil {
+		insertSQL = InsertOld
+	} else {
+		insertSQL = InsertNew
 	}
+	stmt, err := db.Prepare(insertSQL)
+	if err != nil {
+		isWriting = false
+		Log.Error("error in prepare insert telegram ", zap.Error(err))
+		return err
+	}
+
+	defer stmt.Close()
+	result, err := stmt.Exec(teleString)
+	if err != nil {
+		isWriting = false
+		Log.Error("error in insert telegram ", zap.Error(err))
+		return err
+	}
+	id, _ := result.LastInsertId()
+	isWriting = false
+	if insertSQL == InsertOld {
+		Log.Info("telegram processed ", zap.Int64("id", id))
+	} else {
+		Log.Info("telegram saved ", zap.Int64("id", id))
+	}
+	return nil
 }
 
 func LoadUnprocessed() {