Implement scan progress dashboard

[jdfalk]

Summary

• show scan progress on React dashboard
• track scan results via new scanStatus handler
• add progress callback in scanner package
• expand webserver tests for scan endpoints
• rebuild embedded web UI
• update proof-of-concept checklist

Testing

• go test ./pkg/webserver -run TestScanHandlers -count=1 -v
• go test ./...

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https://chatgpt.com/codex/tasks/task_e_6847714067ec8321be4562d664c6867a

[Copilot]

Pull Request Overview

This PR implements a scan progress dashboard by adding new REST endpoints, updating UI components, and expanding test coverage for scan functionality. Key changes include the introduction of the Dashboard component in the web UI, backend handlers for scan operations, and a progress callback in the scanner package.

Reviewed Changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
webui/src/Dashboard.jsx	New React component to display scan status and progress.
webui/src/App.jsx	Updated to include navigation between dashboard and settings.
pkg/webserver/server_test.go	Added tests to verify the new scan endpoints.
pkg/webserver/server.go	Registered the scan and scan status endpoints with appropriate middleware.
pkg/webserver/scan.go	Implemented scan handler and status tracking with a global state and synchronization lock.
pkg/scanner/progress_test.go	Added test to verify that the progress callback is invoked correctly.
pkg/scanner/progress.go	Introduced progress callback functionality using a worker pool for processing video files.
POC.md	Updated checklist to reflect completion of the dashboard progress display.

Files not reviewed (1)

• webui/package-lock.json: Language not supported