Revert "feat(reports): add onboarding empty state for first-time users #817"

[utksh1]

Reverts #1222

[utksh1]

Closing revert PR. The original code changes have already been reverted on main.

[utksh1]

These 22 revert PRs (#1283–#1304) are byte-for-byte identical — each carries the exact same 5,299-line diff (+474/−3680 across the same 47 files), despite each claiming to revert a different PR. A genuine git revert <merge-commit> of distinct commits would produce distinct diffs, so these were not generated by reverting the named PRs; they are 22 duplicate branches carrying one shared mass-deletion.

Closing as invalid because:

• They are duplicates of each other (only one could ever merge; the rest would immediately conflict).
• The shared diff is destructive: it deletes 12 files (incl. backend/secuscan/rate_limiter.py, the webhook-egress policy integration test, four finding_intelligence unit tests, Reports.onboarding.test.tsx) and strips ~3,680 lines from auth.py, executor.py, routes.py, notification_service.py, and several frontend pages.
• None corresponds cleanly to the single PR it nominally reverts.

If a rollback of a specific merged PR is actually wanted, please open one PR per merge using git revert <merge-commit> so each diff is scoped and reviewable. Happy to help scope that.