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/telegram.go

@@ -9,8 +9,10 @@ import (
 )
 
 const (
-	EndTag     = "NNNN"
-	Expression = "(?s)ZCZC.*NNNN"
+	EndTag         = "NNNN"
+	Expression     = "(?s)ZCZC.*?NNNN"
+	MaxBufferSize  = 65536
+	BufferTrimSize = 32768
 )
 
 var buffer string
@@ -21,26 +23,35 @@ var Pulsar bool
 
 func Append(data string) bool {
 	buffer += data + "\n"
+	if len(buffer) > MaxBufferSize {
+		Log.Warn("buffer overflow, truncating",
+			zap.Int("size", len(buffer)),
+			zap.Int("max", MaxBufferSize))
+		buffer = buffer[len(buffer)-BufferTrimSize:]
+	}
 	return check()
 }
 
 func check() bool {
 	teleString := buffer
-	if strings.Index(teleString, EndTag) > 0 {
-		telegram := exp.FindString(teleString)
-		if len(telegram) > 0 {
-			// Log.Info("telegram ", zap.String("text", telegram))
+	if strings.Contains(teleString, EndTag) {
+		loc := exp.FindStringIndex(teleString)
+		if loc != nil {
+			telegram := teleString[loc[0]:loc[1]]
 			telegram = removeEmpty(telegram) + "\n\n"
 			telegram += "\n"
 			_, _ = RawLog.Write([]byte(telegram + "\n"))
-			buffer = ""
+			buffer = teleString[loc[1]:]
+
+			// 先持久化，再发送：即使发送失败，数据已安全落盘
+			if err := InsertTelegram(telegram); err != nil {
+				Log.Error("error in save telegram to db", zap.Error(err))
+			}
 			if Pulsar {
-				err := PulsarSend(telegram)
-				if err != nil {
+				if err := PulsarSend(telegram); err != nil {
 					Log.Error("error in send to pulsar", zap.Error(err))
 				}
 			}
-			InsertTelegram(telegram)
 			return true
 		}
 	}