fix(pos): keep Actual Amount focus stable on close shift

[souravs72]

Summary

• Payment Reconciliation Actual Amount fields no longer grey out / lose focus after 1–2 keystrokes.
• Freeze card color and Over/Short badges while the field is focused; switch to native inputs (same Opening | Expected | Actual layout).
• Pause the POS clock tick while Close Shift is open so parent re-renders do not wipe in-progress amounts.

Test plan

• Open an active shift → Close Shift → Payment Reconciliation
• Click directly in Credit Card Actual Amount (not only the label) and type — focus stays, value sticks
• Repeat for Cash; confirm Over/Short badges appear after blur
• Confirm Close Shift enables only after all methods have a non-empty actual amount
• Confirm layout remains Opening | Expected | Actual Amount (no redesign)