Independent Per-Profile Extensions Support

Multiple profiles should have fully independent extension lists.

Description:
Any profile can install any extension at will. However, extensions installed in one profile are not shared with or available in other profiles. Each profile maintains its own separate set of installed extensions. The same extension can be installed independently in multiple profiles if the user wants.

Current behavior: Extensions installed anywhere are shared globally across all profiles.

Example use case:

Profile 1 (Family): Install only family-friendly extensions.

Profile 2 (Adult): Install adult extensions.

Adult extensions remain unavailable in Profile 1 unless explicitly installed there.

Benefit: Enhanced privacy, parental controls, and user segmentation without global sharing.

Acknowledgements

• My suggestion is NOT about adding a new provider
• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.

No implementation files, tests, or entry points are identified in the issue. Start by locating how profiles store installed extensions and how extension availability is currently shared, then trace installation and profile-selection flows. Done means each profile has an independent extension set while allowing the same extension to be installed separately in multiple profiles.