Excel Sync Client for Windows

I need a lightweight Windows desktop client compiled against .NET 10 LTS that can sit on a trader’s machine, watch a large Excel workbook containing our inventory, spot any content-level edits the moment they happen, and immediately push those deltas to our existing REST API. Only cell value changes matter—row inserts, sheet renames or other structural shifts can be ignored—so the detection logic should favour raw speed over exhaustive comparison.

The app must be a single, self-contained EXE that installs with zero technical fuss: no frameworks to fetch, no command line switches, just click-and-run. Traders should receive clear on-screen confirmations for every sync, along with an error message if the API is unreachable or a row fails validation. Please keep the UI simple: think small status panel, colour cues, maybe a subtle pop-up—nothing noisy that clutters their workspace.

Performance is critical. Workbooks regularly exceed 100 MB, so memory-mapped I/O or streaming approaches are welcome as long as the initial scan stays responsive. Network calls will use our JSON REST endpoints (I’ll supply the Swagger spec); the client should batch changes when possible to reduce chatter but still feel real-time.

Deliverables:
• Signed x64 EXE built with .NET 10 LTS
• Well-structured C# source (Git repo)
• Minimal user guide covering install, first-run, and troubleshooting

I’ll consider the project complete once the client:
1. Loads a sample 100 MB workbook in under 5 seconds on a typical trading PC.
2. Detects cell edits within 2 seconds and posts the correct JSON payload to the API.
3. Shows success or failure feedback instantly, with any errors logged to an optional text file in the app folder.