feat: release v1.0.3 with flattened JSON output structure

- breaking: remove apache and network subdivisions from JSON output
- feat: all log fields now merged into single-level JSON structure
- feat: custom MarshalJSON() implementation for flat output
- chore: update ClickHouse schema to use single fields JSON column
- docs: update CHANGELOG.md and README.md with v1.0.3 changes
- build: bump version to 1.0.3 in build.sh and RPM spec

Migration notes:
- Existing ClickHouse tables need schema migration to use fields JSON column
- Replace apache JSON and network JSON columns with fields JSON column

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

internal/adapters/outbound/clickhouse/sink.go

@@ -234,8 +234,8 @@ func (s *ClickHouseSink) doFlush(ctx context.Context) error {
 	}
 
 	query := fmt.Sprintf(`
-		INSERT INTO %s (timestamp, src_ip, src_port, dst_ip, dst_port, correlated, orphan_side, apache, network)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+		INSERT INTO %s (timestamp, src_ip, src_port, dst_ip, dst_port, correlated, orphan_side, fields)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
 	`, s.config.Table)
 
 	// Retry logic with exponential backoff
@@ -277,8 +277,7 @@ func (s *ClickHouseSink) executeBatch(ctx context.Context, query string, buffer
 	defer stmt.Close()
 
 	for _, log := range buffer {
-		apacheJSON, _ := json.Marshal(log.Apache)
-		networkJSON, _ := json.Marshal(log.Network)
+		fieldsJSON, _ := json.Marshal(log.Fields)
 
 		correlated := 0
 		if log.Correlated {
@@ -293,8 +292,7 @@ func (s *ClickHouseSink) executeBatch(ctx context.Context, query string, buffer
 			log.DstPort,
 			correlated,
 			log.OrphanSide,
-			string(apacheJSON),
-			string(networkJSON),
+			string(fieldsJSON),
 		)
 		if err != nil {
 			return fmt.Errorf("failed to execute insert: %w", err)