Update fefedu973.universal-search-suggestions: add Microsoft Store install source

[Fefedu973]

Summary

• The Universal Search Suggestions extension is now published on the Microsoft Store (product ID 9NCCZNPQB9S6): https://apps.microsoft.com/detail/9nccznpqb9s6
• Add msstore as the primary install source for the extension.
• Keep the GitHub Releases URL as a secondary source for users who prefer manual install.

Test plan

• Verified the Store product ID resolves: ms-windows-store://pdp/?productid=9NCCZNPQB9S6
• id still matches folder path (fefedu973.universal-search-suggestions ↔ fefedu973/universal-search-suggestions/)
• No other fields modified beyond installSources

🤖 Generated with Claude Code

[Fefedu973]

Pushed 5 screenshots to the same branch for the gallery slideshow (per the screenshots/ folder convention in the contributing guide):

• 01-overview.png — rich Wikipedia details panel
• 02-ai-answer-panel.png — streamed AI answer
• 03-local-bookmarks.png — local browser bookmarks/history
• 04-instant-answers.png — inline calculator
• 05-url-detection.png — direct URL detection

All under 1 MB each, PNG, no SVG.