Non-Copilot customization file detection

[FokkoVeegens]

This pull request introduces detection and reporting of "missed potential" workspaces—repositories that contain AI instruction/config files for other tools (like Cursor, Windsurf, Claude, etc.) but lack any Copilot customization files. The goal is to help identify opportunities to encourage Copilot adoption by surfacing these cases in the Usage Analysis dashboard. The implementation involves updates to file scanning patterns, data models, and the UI, as well as new documentation and testing guidance.

Key changes:

Non-Copilot File Detection & Patterns

• Added new patterns for non-Copilot instruction/config files to customizationPatterns.json, each with a category: "non-copilot" field and relevant metadata (tool name, icon, path, scan mode, etc.). All existing Copilot patterns are now explicitly marked with category: "copilot". [1] [2] [3] [4] [5] [6] [7]

Data Model & Interface Updates

• Extended the CustomizationFileEntry interface to include an optional category field ('copilot' | 'non-copilot').
• Introduced a new MissedPotentialWorkspace interface to represent workspaces with non-Copilot files but no Copilot files, and updated UsageAnalysisStats to include an optional missedPotential array.

Scanning & Categorization Logic

• Updated the file scanning logic in scanWorkspaceCustomizationFiles() to attach the category from the pattern to each discovered file entry. [1] [2]

Design & Documentation

• Added a comprehensive design spec (docs/specs/nonCopilotFilesDetection.md) detailing the motivation, requirements, implementation plan, file patterns, UI/UX, and verification steps for this feature.

These changes lay the groundwork for surfacing "missed potential" workspaces in the dashboard and make it easy to extend detection to new tools in the future.

[Copilot]

Pull request overview

This PR adds “missed potential” detection to the Usage Analysis dashboard by identifying workspaces that contain non-Copilot AI tool instruction/config files (e.g., Cursor/Windsurf/Claude) but have no Copilot customization files, and then surfacing those workspaces in the UI.

Changes:

• Extends customization scanning to tag discovered files with a category (copilot vs non-copilot) and computes a missedPotential workspace list in usage analysis stats.
• Updates the Usage Analysis webview to render a new “Missed Potential” section/table.
• Expands customizationPatterns.json with non-Copilot detection patterns and adds a design/spec document.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
src/extension.ts	Adds category propagation during scanning, computes missedPotential, and includes it in stats sent to the Usage Analysis webview.
src/webview/usage/main.ts	Adds types and UI rendering for the new “Missed Potential” section.
src/customizationPatterns.json	Introduces category for existing patterns and adds non-Copilot tool patterns.
docs/specs/nonCopilotFilesDetection.md	Adds a design/spec describing goals, detection approach, and UI behavior.