Frontend/new session

[MaddieWright]

New session

What?

Added a "New" button to the settings bar that allows users to start a fresh session, with a warning dialog when there are unsaved changes and a success toast when new session is started.

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How?

• Added a New button with a + icon in the settings bar, placed between the session info Menubar and the progress slider.

Clicking "New" either immediately clears the pipeline or shows a warning dialog first, depending on whether the current session has unsaved changes:

• Unsaved changes (isDirty = true): shows a confirmation dialog warning the user that unsaved changes will be lost
• No unsaved changes: immediately clears the pipeline without prompting
• isDirty is tracked by listening to canvas-changed and reactflow-edges-changed custom window events (fired when
• nodes/edges are added or modified). It resets to false after a successful save or when the user starts a fresh session.

Confirming "New" stops the data stream, resets the timer, clears all nodes and edges via the pipeline-reset event, and sets activeSessionId to null.

Also replaced MenubarTrigger with plain button elements for the "Tutorials" item (and initially "New") to prevent Radix UI's open/closed state from leaving a persistent hover highlight after click.

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Testing

• Confirmed clicking "New" with no changes immediately clears the pipeline (no dialog shown)
• Confirmed clicking "New" after adding nodes shows the warning dialog
• Confirmed clicking "Cancel" in the dialog leaves the pipeline intact
• Confirmed clicking "Confirm" clears all nodes/edges and resets the timer and stream
• Confirmed isDirty resets after saving, so clicking "New" immediately after a save does not prompt the warning
• Confirmed "New" button is disabled while a save/load operation is in progress
• Confirmed no persistent hover highlight on the Tutorials button after fix