ux(admin): use display label in PayrollAdjustment admin list column

Code-review follow-up on 1cf1304. /admin/core/payrolladjustment/
was still showing raw DB values (New Loan / Advance Payment /
Advance Repayment) in the Type list column because list_display
was the bare field name 'type', which Django renders via
str(obj.type).

Added a @admin.display method that returns obj.get_type_display()
and referenced it in list_display instead. Column header stays
'Type' and the column is still sortable by the underlying field.

list_filter kept on 'type' (DB value) - filter sidebar correctness
doesn't require the display label, and filtering works off the
canonical stored value.

Closes the last known "users see shorter labels everywhere" gap
from the Path A rename.

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

core/admin.py

@@ -114,10 +114,19 @@ class LoanAdmin(admin.ModelAdmin):
 
 @admin.register(PayrollAdjustment)
 class PayrollAdjustmentAdmin(admin.ModelAdmin):
-    list_display = ('worker', 'type', 'amount', 'date')
+    list_display = ('worker', 'type_display', 'amount', 'date')
     list_filter = ('type', 'date', 'worker')
     search_fields = ('worker__name', 'description')
 
+    # === Type column uses the short user-facing label ===
+    @admin.display(description='Type', ordering='type')
+    def type_display(self, obj):
+        """Show the short user-facing label (e.g. "Loan", "Advance")
+        instead of the raw DB value ("New Loan", "Advance Payment").
+        Sorting and filtering still work off the underlying `type`
+        field — this only changes what's printed in the column."""
+        return obj.get_type_display()
+
 class ExpenseLineItemInline(admin.TabularInline):
     model = ExpenseLineItem
     extra = 1