Polish settings navigation and Heroicon hierarchy

[mehul0810]

Summary

• standardize settings actions and dashboard status visuals on semantic Heroicons
• simplify the crowded primary navigation by grouping advanced reports under Diagnostics without changing their existing URLs
• refine dashboard cards, status badges, typography, spacing, and action hierarchy for a calmer enterprise presentation
• preserve responsive stacking and add keyboard navigation for the Diagnostics sub-navigation
• correct the Bloat label from "Disable Emoji's" to "Disable Emojis"

Validation

• PATH=/Users/mehulgohil/.nvm/versions/node/v24.16.0/bin:$PATH npm run test:unit -- --runInBand (12 suites, 41 tests)
• PATH=/Users/mehulgohil/.nvm/versions/node/v24.16.0/bin:$PATH npm run lint
• PATH=/Users/mehulgohil/.nvm/versions/node/v24.16.0/bin:$PATH npm run build
• composer lint (91 files)
• composer test (148 tests, 482 assertions)
• rendered desktop and 390px checks on the local Perform settings page
• verified 20 dashboard Heroicons have paths, usable dimensions, and decorative aria-hidden treatment
• verified no document-level overflow at desktop or 390px
• verified arrow-key navigation from Site Inventory to Database updates the canonical tab URL

Notes

• composer check-cs is not used as change proof because the repository-wide configuration currently scans existing JavaScript/config files with PHP sniffs and reports unrelated baseline violations.

[github-actions]

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