feat(invoices): invoice list column sorting and row-level status styling (#1375)

* feat(invoices): add column sorting and row-level status styling to invoice list

Client-side sorting on number, customer, due date, amount and status with
Swedish collation, null-last ordering and stable date/id tie-breaks. Status
chips move to the shared RowStatus descriptor so normal states stay muted and
exceptions carry semantic color. Invoice fetch now pages past the PostgREST
1000-row cap via fetchAllRows so sorting covers the full list.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* test(invoices): make rounded-amount sort assertions non-degenerate

Distinct rounded totals now prove the comparator orders by displayed value;
the rounded tie case is kept as an explicit tie-breaker test since integer
rounding is monotonic and can only create ties, never reorder.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

messages/en.json

@@ -5375,6 +5375,7 @@
     "th_due": "Due",
     "th_amount": "Amount",
     "th_status": "Status",
+    "sort_by": "Sort by {column}",
     "create_invoice_desc": "Regular customer invoice",
     "create_recurring": "Recurring invoice",
     "create_recurring_desc": "Created automatically, e.g. every month",

messages/sv.json

@@ -5375,6 +5375,7 @@
     "th_due": "Förfaller",
     "th_amount": "Belopp",
     "th_status": "Status",
+    "sort_by": "Sortera efter {column}",
     "create_invoice_desc": "Vanlig kundfaktura",
     "create_recurring": "Återkommande faktura",
     "create_recurring_desc": "Skapas automatiskt, till exempel varje månad",