Add -out option for file output and fix stdin detection logic

- Add -out/-o option to save decode/encode output to files
- Encoded files are saved as binary, console still shows hex strings
- Decoded XML files are saved as text
- Fix stdin detection logic to prioritize command line arguments
- Add missing System.Collections.Generic import for List<string> usage
- File extension auto-processing now supports -out option
- Clean up data folder with renamed files (data0-3.dump/xml)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Data/Dump/01_V2GMSG-SDP_Request.txt

@@ -0,0 +1,5 @@
+0000   33 33 00 00 00 01 10 22 33 44 55 66 86 dd 60 00   33....."3DUf..`.
+0010   00 00 00 12 11 ff fe 80 00 00 00 00 00 00 12 22   ..............."
+0020   33 ff fe 44 55 66 ff 02 00 00 00 00 00 00 00 00   3..DUf..........
+0030   00 00 00 00 00 01 c3 51 3b 0e 00 12 c8 18 01 fe   .......Q;.......
+0040   90 00 00 00 00 02 10 00                           ........

Data/Dump/02_V2GMSG-SDP_Response.txt

@@ -0,0 +1,6 @@
+0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
+0010   00 00 00 24 11 ff fe 80 00 00 00 00 00 00 82 34   ...$...........4
+0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
+0030   33 ff fe 44 55 66 3b 0e c3 51 00 24 5e 42 01 fe   3..DUf;..Q.$^B..
+0040   90 01 00 00 00 14 fe 80 00 00 00 00 00 00 82 34   ...............4
+0050   28 ff fe 2e 23 dd d1 21 10 00                     (...#..!..

Data/Dump/03-V2GMSG-SAP_SupportedAppProtocolReq.txt

@@ -0,0 +1,8 @@
+0000   80 34 28 2e 23 dd 10 22 33 44 55 66 86 dd 60 00   .4(.#.."3DUf..`.
+0010   00 00 00 40 06 ff fe 80 00 00 00 00 00 00 12 22   ...@..........."
+0020   33 ff fe 44 55 66 fe 80 00 00 00 00 00 00 82 34   3..DUf.........4
+0030   28 ff fe 2e 23 dd c3 65 d1 21 00 63 9b 07 2c c5   (...#..e.!.c..,.
+0040   4a 30 50 18 11 1c d4 f8 00 00 01 fe 80 01 00 00   J0P.............
+0050   00 24 80 00 eb ab 93 71 d3 4b 9b 79 d1 89 a9 89   .$.....q.K.y....
+0060   89 c1 d1 91 d1 91 81 89 99 d2 6b 9b 3a 23 2b 30   ..........k.:#+0
+0070   02 00 00 0c 38 40                                 ....8@

Data/Dump/04-V2GMSG-SAP_SupportedAppProtocolRes.txt

@@ -0,0 +1,6 @@
+0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
+0010   00 00 00 20 06 ff fe 80 00 00 00 00 00 00 82 34   ... ...........4
+0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
+0030   33 ff fe 44 55 66 d1 21 c3 65 2c c5 4a 30 00 63   3..DUf.!.e,.J0.c
+0040   9b 33 50 18 0b 3c 96 5f 00 00 01 fe 80 01 00 00   .3P..<._........
+0050   00 04 80 40 00 c0                                 ...@..

Data/dump0.dump

@@ -1,7 +0,0 @@
-0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
-0010   00 00 00 33 06 ff fe 80 00 00 00 00 00 00 82 34   ...3...........4
-0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
-0030   33 ff fe 44 55 66 d1 21 c3 65 2c c5 61 f8 00 63   3..DUf.!.e,.a..c
-0040   ae c9 50 18 08 a8 72 51 00 00 01 fe 80 01 00 00   ..P...rQ........
-0050   00 17 80 98 02 10 50 90 8c 0c 0c 0e 0c 51 80 00   ......P......Q..
-0060   00 00 20 40 c4 08 a0 30 00                        .. @...0.

Data/test_decode.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ns1:V2G_Message xmlns:ns1="urn:iso:15118:2:2013:MsgDef" xmlns:ns2="urn:iso:15118:2:2013:MsgHeader" xmlns:ns3="urn:iso:15118:2:2013:MsgBody" xmlns:ns4="urn:iso:15118:2:2013:MsgDataTypes">
+  <ns1:Header>
+    <ns2:SessionID>4142423030303831</ns2:SessionID>
+  </ns1:Header>
+  <ns1:Body>
+    <ns3:WeldingDetectionReq>
+      <ns3:DC_EVStatus>
+        <ns4:EVReady>True</ns4:EVReady>
+        <ns4:EVErrorCode>NO_ERROR</ns4:EVErrorCode>
+        <ns4:EVRESSSOC>100</ns4:EVRESSSOC>
+      </ns3:DC_EVStatus>
+    </ns3:WeldingDetectionReq>
+
+  </ns1:Body>
+</ns1:V2G_Message>

Data/test_exi.hex

@@ -1 +0,0 @@
-8098021050908C0C0C0E0C5211003200