docs: correct Salary verification step (manual amount entry, not auto-filled)

Final whole-feature review flagged the design doc's verification
checklist step 4 over-promised an auto-filled amount. Manual entry is
intentional; corrected so Konrad's local verification expectations match
actual behaviour. Docs-only, local-only — feature still NOT pushed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/plans/2026-05-15-manager-salaried-pay-design.md

@@ -248,8 +248,12 @@ managers — do **not** add the exclusion there.
    worker picker (admin and, if testable, supervisor).
 3. Existing daily workers + their dashboard/report numbers are unchanged
    (spot-check Outstanding + a project's Labour Cost before/after Fitz exists).
-4. "Pay Salary" for Fitz → pick project, amount defaults to his salary,
-   Pay Immediately → payslip generated, `PayrollRecord` visible in history.
+4. "Pay Salary" for Fitz → modal opens pre-set to type=Salary with Pay
+   Immediately ticked; **select Fitz, pick a project, and type the amount
+   manually** (the amount is NOT auto-filled from his stored salary — manual
+   entry is intentional, since the actual monthly figure can differ and the
+   modal supports multi-select) → payslip generated (clean single Salary
+   line, no "0 days worked"), `PayrollRecord` visible in history.
 5. Add a **Loan** and a **Deduction** to Fitz → both appear in his
    worker-lookup card and the Loans / Adjustments tabs; net pay correct.
 6. `/report/` → Fitz's salary shows under the project's