add pipeline struct to replace ProcessingConfig and WindowingConfig

[itang06]

What?

combined ProcessingConfig and WindowingConfig structs into a single Pipeline struct that the frontend sends as one JSON message at the start of a WebSocket session

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How?

• Created pipeline.rs in shared-logic with a Pipeline struct containing a Vec<Node>, where Node is an enum with Window, Preprocessing, and ML variants, with each carrying their own config struct
• Removed ProcessingConfig and WindowingConfig from lsl.rs and replaced references throughout lsl.rs, bc.rs, and websocket-server/main.rs with the new Pipeline type
• Simplified handle_connection in main.rs to loop until the first non null text message (pipeline JSON) instead of the previous 500ms timeout phase that waited for two separate config messages
• Changed session_id to String in WebSocketInitMessage to match the frontend's type

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Testing

• cargo check passes w/o errors
• Connected to ws://localhost:8080 via Postman and sent the pipeline JSON, and Docker logs confirmed Received pipeline with 3 nodes and EEG data packets streamed back successfully

postman message

docker logs

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[github-actions]

❌ PR approval conditions NOT satisfied. At least 1 team lead OR 2 team members must approve before merging.
[Last checked: 2026-04-04T20:12:15.350Z]