Fix second Argument-list-too-long spot in cmd_import

The command_id extraction passed the full command-submission
response (which echoes back the whole files array) as a python argv
arg - same ARG_MAX issue as the api_post fix, one step later. Now
piped via stdin. The actual command submission already worked with
the first fix; this only affected reading back the response.

Claude-Session: https://claude.ai/code/session_01HZQK6jHmdTpFjFZM8FUnqA

sonarr.sh

@@ -301,7 +301,7 @@ print(json.dumps({'name': 'ManualImport', 'files': files, 'importMode': 'auto'})
     local response
     response=$(api_post "command" "$payload")
     local command_id
-    command_id=$(python3 -c "import json,sys; print(json.loads(sys.argv[1])['id'])" "$response")
+    command_id=$(echo "$response" | python3 -c "import json,sys; print(json.load(sys.stdin)['id'])")
 
     # Poll for completion
     for _ in $(seq 1 30); do