Implement universal share/export feature

[tessellis]

Description

Implement an export/import feature for the top menu to allow users to come back to past work or share with others

Functional Notes

• Users should be able to export/import their workspace. This can save past work they want to go back to or share with others.
• The feature button will be located in the top menu, with a "share" icon
• The file format used is JSON

Visuals

Feature Button

[rebmoreno]

Overview

Added the ability to save and restore the full workspace state to/from a JSON file, including retrieved data, sound module configurations, and all toolbar settings.

Export

• Serializes current workspace state using captureState()
• Includes retrieved sensor data so it doesn't need to be
  re-fetched on import
• Downloads as ear2earth_workspace_YYYY-MM-DD.json
• Shows success status message on completion

Import

• Reads and parses a JSON workspace file
• Shows Importing workspace... message immediately for feedback
• Restores all state via restoreState()
• Caches retrieved data to avoid redundant fetches
• Shows success or error status message on completion
• Validates file format and shows error if invalid

Known Limitations

• Large datasets may take a few seconds to import
• Imported file must be a valid ear2earth workspace JSON

Visuals

Testing

Export

• Export with data loaded — verify JSON contains retrievedData
• Export with no data — verify JSON exports without retrievedData
• Export with multiple sound modules — verify all modules saved
• Verify filename format is ear2earth_workspace_YYYY-MM-DD.json
• Verify success status message appears after export

Import

• Import a valid workspace file with data — verify plots restore
• Import a valid workspace file without data — verify empty state
• Import with multiple sound modules — verify all modules restore
• Import an invalid JSON file — verify error message appears
• Verify "Importing workspace..." message appears immediately
• Verify "Workspace imported!" message appears on success
• Verify BPM, volume, speed, sensor/reading selections all restore
• Verify date range state restores correctly

Round Trip

• Export then import — verify workspace is identical
• Export, change settings, import — verify reverts to saved state