- Replace string.Empty stub with full BuildHtml implementation
- Self-contained HTML with inline CSS and JS — no external dependencies
- toggle(i) JS function with collapsible subfolder rows (sf-{i} IDs)
- _togIdx counter reset at start of each BuildHtml call (per PS pattern)
- RenderNode/RenderChildNode for recursive tree rendering
- FormatSize helper: B/KB/MB/GB adaptive display
- HtmlEncode via System.Net.WebUtility
- Add explicit System.IO using (required in WPF project)
- Stats cards: Total Entries, Unique Permission Sets, Distinct Users/Groups
- Type badges: site-coll (blue), site (green), list (amber), folder (gray)
- Unique/Inherited badges based on HasUniquePermissions flag
- User pills with external-user CSS class for #EXT# logins
- Inline JS filterTable() function for client-side row filtering
- WriteAsync uses UTF-8 without BOM for HTML
- All 3 HtmlExportServiceTests pass
[Rule 3 - Blocking] CsvExportService/HtmlExportService stubs added so export test
files compile. [Rule 1 - Bug] PermissionsService: removed Principal.Email (not on
Principal, only on User) and changed folder param from Folder to ListItem (SecurableObject).
