fix(kuasa-pajak): restore taxpayer profile access ## Changes The kuasa taxpayer profile called a staff-only reader, so ordinary tax agents received a server-render error. Production logs tied digest `3346619843` to the dashboard access denial. Use the existing active-assignment reader with the scoped kuasa ID and retain the not-found response when access is unavailable. Add route regression coverage for an active nonstaff assignment, denied detail access, and a failed route scope. Closes #1929 ## Release impact Patch. Restore intended profile access in the existing kuasa workflow. ## Migration notes None. ## Validation - UI syntax audits passed. - React Doctor changed audit against `d0356c1c38da9371687e88976d866f84300487f2` passed with zero errors, zero warnings, and complete checks. - Regression file syntax and `git diff --check` passed. - Regression tests, build, and dev were not run, per user instruction.