Load existing result files into Attachments dropdown on plot open

[IanMayo]

Bug Description

When running a tool (e.g., range-bearing), the result file is saved to the assets folder and appears in the Attachments dropdown with a yellow halo. However, if the plot is closed and reopened, the result files are not shown in the Attachments dropdown.

Expected Behavior

When opening a plot, scan the assets/ directory for existing result files and populate the Attachments dropdown.

Current Behavior

• Tool execution saves result to assets/range-bearing-*.json
• Result appears in Attachments dropdown during session
• After closing and reopening plot, Attachments shows empty Results section

Implementation Needed

1. In openPlot.ts or stacService, scan assets/ folder for result files when loading plot
2. Filter for result files (e.g., files with debrief:toolId metadata or naming convention)
3. Pass result files to activityPanelProvider.setResultFiles() or similar
4. Populate the Attachments dropdown on load

Related

• Feature 048: Refactor VS Code map wrapper
• Issue Wire up file actions in Associated Files dropdown #171: Wire up file actions in Associated Files dropdown