feat(tracker): multi-select bulk pay/skip (plan C3)

- Add a leading selection checkbox to each desktop + mobile row, threaded from
  the page through TrackerBucket via an optional RowSelection prop (renders only
  when the page supplies a toggle handler).
- Page owns the selection Set; a sticky bottom action bar appears when ≥1 bill is
  checked: "N selected · Pay · Skip · Clear".
- Pay selected reuses the bulkPay item shape + Undo from "Pay all due".
- Skip selected fans out saveBillMonthlyState (no bulk endpoint; skip has no money
  effect) with Promise.allSettled, an aggregated "n skipped / m failed" toast, and
  an Undo that un-skips. Selection clears on month change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/components/tracker/MobileTrackerRow.tsx

@@ -6,6 +6,7 @@ import { api } from '@/api';
 import { cn, fmt, fmtDate, errMessage } from '@/lib/utils';
 import { asDollars } from '@/lib/money';
 import { Button } from '@/components/ui/button';
+import { Checkbox } from '@/components/ui/checkbox';
 import { Input } from '@/components/ui/input';
 import {
   AlertDialog, AlertDialogContent, AlertDialogHeader, AlertDialogTitle,
@@ -63,6 +64,13 @@ export interface MoveControls {
   moving?: boolean;
 }
 
+// Per-row multi-select state supplied by the bucket. When present, the row shows
+// a leading checkbox that adds/removes it from the page-level selection.
+export interface RowSelection {
+  selected: boolean;
+  onToggle: (next: boolean) => void;
+}
+
 interface MobileTrackerRowProps {
   row: TrackerRow;
   year: number;
@@ -73,9 +81,10 @@ interface MobileTrackerRowProps {
   moveControls?: MoveControls;
   dragProps?: DragProps;
   isDrifted?: boolean;
+  selection?: RowSelection;
 }
 
-export function MobileTrackerRow({ row, year, month, refresh, index, onEditBill, moveControls, dragProps, isDrifted = false }: MobileTrackerRowProps) {
+export function MobileTrackerRow({ row, year, month, refresh, index, onEditBill, moveControls, dragProps, isDrifted = false, selection }: MobileTrackerRowProps) {
   const amountRef                     = useRef<HTMLInputElement>(null);
   const [paymentLedgerOpen, setPaymentLedgerOpen] = useState(false);
   const [confirmUnpay, setConfirmUnpay] = useState(false);
@@ -177,6 +186,15 @@ export function MobileTrackerRow({ row, year, month, refresh, index, onEditBill,
       >
         <div className="flex min-w-0 items-start justify-between gap-3">
           <div className="flex min-w-0 gap-2">
+            {selection && (
+              <div className="flex shrink-0 items-center pt-0.5">
+                <Checkbox
+                  checked={selection.selected}
+                  onCheckedChange={(v) => selection.onToggle(v === true)}
+                  aria-label={`Select ${row.name}`}
+                />
+              </div>
+            )}
             <div className="flex shrink-0 items-center gap-0.5 pt-0.5">
               <GripVertical
                 className={cn(

client/components/tracker/TrackerBucket.tsx

@@ -18,7 +18,7 @@ import {
 } from '@/lib/trackerUtils';
 import { DEFAULT_TRACKER_TABLE_COLUMNS } from '@/lib/trackerTableColumns';
 import { TrackerRow as Row } from '@/components/tracker/TrackerRow';
-import { MobileTrackerRow, type DragProps, type MoveControls } from '@/components/tracker/MobileTrackerRow';
+import { MobileTrackerRow, type DragProps, type MoveControls, type RowSelection } from '@/components/tracker/MobileTrackerRow';
 import type { Payment, TrackerRow } from '@/types';
 
 interface SortableHeadProps {
@@ -76,6 +76,8 @@ interface TrackerBucketProps {
   onSort?: (key: string) => void;
   driftedIds?: Set<number>;
   visibleColumns?: string[];
+  selectedIds?: Set<number>;
+  onToggleSelect?: (id: number, next: boolean) => void;
 }
 
 export function TrackerBucket({
@@ -94,9 +96,14 @@ export function TrackerBucket({
   onSort,
   driftedIds = new Set<number>(),
   visibleColumns = DEFAULT_TRACKER_TABLE_COLUMNS,
+  selectedIds,
+  onToggleSelect,
 }: TrackerBucketProps) {
   const [draggingId, setDraggingId] = useState<number | null>(null);
   const [dropTargetId, setDropTargetId] = useState<number | null>(null);
+  // Build the per-row selection prop only when the page provides a toggle handler.
+  const selectionFor = (r: TrackerRow): RowSelection | undefined =>
+    onToggleSelect ? { selected: selectedIds?.has(r.id) ?? false, onToggle: (next) => onToggleSelect(r.id, next) } : undefined;
   const visibleColumnSet = new Set(visibleColumns);
   const showColumn = (key: string) => visibleColumnSet.has(key);
   const tableColSpan = 1 + visibleColumns.length;
@@ -343,6 +350,7 @@ export function TrackerBucket({
               moveControls={moveControlsFor(r, i)}
               dragProps={dragPropsFor(r, i)}
               isDrifted={driftedIds.has(r.id)}
+              selection={selectionFor(r)}
             />
           ))
         )}
@@ -437,6 +445,7 @@ export function TrackerBucket({
                     dragProps={dragPropsFor(r, i)}
                     isDrifted={driftedIds.has(r.id)}
                     visibleColumns={visibleColumns}
+                    selection={selectionFor(r)}
                   />
                 ))}
               </LayoutGroup>

client/components/tracker/TrackerRow.tsx

@@ -6,6 +6,7 @@ import { api } from '@/api';
 import { cn, fmt, fmtDate, errMessage } from '@/lib/utils';
 import { asDollars, type Dollars } from '@/lib/money';
 import { Button } from '@/components/ui/button';
+import { Checkbox } from '@/components/ui/checkbox';
 import { Input } from '@/components/ui/input';
 import {
   TableRow, TableCell,
@@ -23,7 +24,7 @@ import { PaymentLedgerDialog } from '@/components/tracker/PaymentLedgerDialog';
 import { NotesCell } from '@/components/tracker/NotesCell';
 import { AutopaySuggestionActions } from '@/components/tracker/AutopaySuggestionActions';
 import type { TrackerRow as TrackerRowData } from '@/types';
-import type { DragProps, MoveControls } from '@/components/tracker/MobileTrackerRow';
+import type { DragProps, MoveControls, RowSelection } from '@/components/tracker/MobileTrackerRow';
 
 // Cast type for the HTML5 drag handlers, which conflict with framer-motion's own
 // onDrag* gesture types on the motion.tr-backed TableRow.
@@ -40,9 +41,10 @@ interface TrackerRowProps {
   dragProps?: DragProps;
   isDrifted?: boolean;
   visibleColumns?: string[];
+  selection?: RowSelection;
 }
 
-export function TrackerRow({ row, year, month, refresh, index, onEditBill, moveControls, dragProps, isDrifted, visibleColumns = DEFAULT_TRACKER_TABLE_COLUMNS }: TrackerRowProps) {
+export function TrackerRow({ row, year, month, refresh, index, onEditBill, moveControls, dragProps, isDrifted, visibleColumns = DEFAULT_TRACKER_TABLE_COLUMNS, selection }: TrackerRowProps) {
   const amountRef                     = useRef<HTMLInputElement>(null);
   const [paymentLedgerOpen, setPaymentLedgerOpen] = useState(false);
   const [confirmUnpay, setConfirmUnpay] = useState(false);
@@ -306,6 +308,14 @@ export function TrackerRow({ row, year, month, refresh, index, onEditBill, moveC
         {/* Bill name + category + monthly notes (if set) */}
         <TableCell className="w-[18%] py-2.5">
           <div className="flex min-w-0 items-center gap-2.5">
+            {selection && (
+              <Checkbox
+                checked={selection.selected}
+                onCheckedChange={(v) => selection.onToggle(v === true)}
+                aria-label={`Select ${row.name}`}
+                className="shrink-0"
+              />
+            )}
             <div className="flex shrink-0 items-center gap-0.5">
               <GripVertical
                 className={cn(

client/pages/TrackerPage.tsx

@@ -316,6 +316,10 @@ export default function TrackerPage() {
   // Row to open in PaymentLedgerDialog via the overdue command center
   const [commandCenterPayRow, setCommandCenterPayRow] = useState<TrackerRow | null>(null);
 
+  // Multi-select: bill ids checked for a bulk pay/skip action.
+  const [selectedIds, setSelectedIds] = useState<Set<number>>(new Set());
+  const [bulkBusy, setBulkBusy] = useState(false);
+
   // Use React Query for data fetching
   const { data, isLoading: loading, isError, error, refetch, dataUpdatedAt } = useTracker(year, month);
   const { data: driftDataRaw } = useDriftReport();
@@ -343,6 +347,10 @@ export default function TrackerPage() {
     setMovingBillId(null);
   }, [dataUpdatedAt, year, month]);
 
+  // Clear a stale multi-selection when navigating months (survives background
+  // refetches within the same month).
+  useEffect(() => { setSelectedIds(new Set()); }, [year, month]);
+
   // Surface a settings-load failure (React Query swallows it into isError).
   // The page still renders with TRACKER_SETTING_DEFAULTS.
   useEffect(() => {
@@ -474,7 +482,98 @@ export default function TrackerPage() {
     navigateTo(`/calendar?year=${year}&month=${month}`);
   }
 
+  const handleToggleSelect = useCallback((id: number, next: boolean) => {
+    setSelectedIds(prev => {
+      const s = new Set(prev);
+      if (next) s.add(id); else s.delete(id);
+      return s;
+    });
+  }, []);
+  const clearSelection = useCallback(() => setSelectedIds(new Set()), []);
+
+  // Pay every selected bill that still has a balance, in one bulk call (reuses
+  // the same item shape + Undo as the per-bucket "Pay all due").
+  async function handlePaySelected() {
+    const items = selectedRows
+      .filter(r => !r.is_skipped && !rowIsPaid(r))
+      .map(r => {
+        const threshold = Number(r.actual_amount ?? r.expected_amount ?? 0) || 0;
+        const remaining = Math.max(threshold - (Number(r.total_paid) || 0), 0);
+        return { bill_id: r.id, amount: remaining > 0 ? remaining : threshold, paid_date: paymentDateForTrackerMonth(year, month, r.due_day) };
+      })
+      .filter(item => item.amount > 0);
+    if (items.length === 0) { toast.info('No unpaid bills selected.'); return; }
+    const total = items.reduce((s, i) => s + i.amount, 0);
+    setBulkBusy(true);
+    try {
+      const result = await api.bulkPay(items) as { created?: Array<{ id: number }> };
+      const created = result.created || [];
+      if (created.length === 0) {
+        toast.info('Those bills were already paid.');
+      } else {
+        toast.success(`Paid ${created.length} bill${created.length === 1 ? '' : 's'} — ${fmt(total)}`, {
+          action: {
+            label: 'Undo',
+            onClick: async () => {
+              try {
+                await Promise.all(created.map(p => api.deletePayment(p.id)));
+                toast.success('Payments removed');
+                invalidateData();
+              } catch (err) {
+                toast.error((err as { message?: string })?.message || 'Failed to undo payments.');
+              }
+            },
+          },
+        });
+      }
+      clearSelection();
+      invalidateData();
+    } catch (err) {
+      toast.error((err as { message?: string })?.message || 'Failed to pay bills.');
+    } finally {
+      setBulkBusy(false);
+    }
+  }
+
+  // Skip every selected bill for this month. No bulk endpoint exists (skip has no
+  // money effect), so fan out per-bill and aggregate the result; Undo un-skips.
+  async function handleSkipSelected() {
+    const toSkip = selectedRows.filter(r => !r.is_skipped);
+    if (toSkip.length === 0) { toast.info('No skippable bills selected.'); return; }
+    setBulkBusy(true);
+    try {
+      const results = await Promise.allSettled(
+        toSkip.map(r => api.saveBillMonthlyState(r.id, { year, month, is_skipped: true, actual_amount: r.actual_amount, notes: r.monthly_notes })),
+      );
+      const skipped = toSkip.filter((_, i) => results[i]?.status === 'fulfilled');
+      const failed = results.length - skipped.length;
+      if (skipped.length > 0) {
+        toast.success(`Skipped ${skipped.length} bill${skipped.length === 1 ? '' : 's'}${failed ? ` — ${failed} failed` : ''}`, {
+          action: {
+            label: 'Undo',
+            onClick: async () => {
+              try {
+                await Promise.all(skipped.map(r => api.saveBillMonthlyState(r.id, { year, month, is_skipped: false, actual_amount: r.actual_amount, notes: r.monthly_notes })));
+                toast.success('Restored');
+                invalidateData();
+              } catch (err) {
+                toast.error((err as { message?: string })?.message || 'Failed to undo.');
+              }
+            },
+          },
+        });
+      } else {
+        toast.error('Failed to skip the selected bills.');
+      }
+      clearSelection();
+      invalidateData();
+    } finally {
+      setBulkBusy(false);
+    }
+  }
+
   const rows         = useMemo(() => orderedRows || data?.rows || [], [orderedRows, data]);
+  const selectedRows = useMemo(() => rows.filter(r => selectedIds.has(r.id)), [rows, selectedIds]);
   const summary      = (data?.summary ?? {}) as TrackerSummary;
   const bankTracking = data?.bank_tracking;
   const cashflow     = data?.cashflow;
@@ -1135,8 +1234,8 @@ export default function TrackerPage() {
 
       {!isError && (first.length > 0 || second.length > 0) && (
         <div className="space-y-5">
-          {first.length  > 0 && <Bucket label="1st – 14th"  rows={first}  year={year} month={month} refresh={invalidateData} onEditBill={handleOpenEditBill} loading={loading} reorderEnabled={reorderEnabled} movingBillId={movingBillId} sortKey={sortKey} sortDir={sortDir} onSort={handleSortHeader} onReorderRows={(next) => handleReorderBucket('1st', next)} driftedIds={driftedIds} visibleColumns={visibleTableColumns} />}
-          {second.length > 0 && <Bucket label="15th – 31st" rows={second} year={year} month={month} refresh={invalidateData} onEditBill={handleOpenEditBill} loading={loading} reorderEnabled={reorderEnabled} movingBillId={movingBillId} sortKey={sortKey} sortDir={sortDir} onSort={handleSortHeader} onReorderRows={(next) => handleReorderBucket('15th', next)} driftedIds={driftedIds} visibleColumns={visibleTableColumns} />}
+          {first.length  > 0 && <Bucket label="1st – 14th"  rows={first}  year={year} month={month} refresh={invalidateData} onEditBill={handleOpenEditBill} loading={loading} reorderEnabled={reorderEnabled} movingBillId={movingBillId} sortKey={sortKey} sortDir={sortDir} onSort={handleSortHeader} onReorderRows={(next) => handleReorderBucket('1st', next)} driftedIds={driftedIds} visibleColumns={visibleTableColumns} selectedIds={selectedIds} onToggleSelect={handleToggleSelect} />}
+          {second.length > 0 && <Bucket label="15th – 31st" rows={second} year={year} month={month} refresh={invalidateData} onEditBill={handleOpenEditBill} loading={loading} reorderEnabled={reorderEnabled} movingBillId={movingBillId} sortKey={sortKey} sortDir={sortDir} onSort={handleSortHeader} onReorderRows={(next) => handleReorderBucket('15th', next)} driftedIds={driftedIds} visibleColumns={visibleTableColumns} selectedIds={selectedIds} onToggleSelect={handleToggleSelect} />}
         </div>
       )}
 
@@ -1215,6 +1314,48 @@ export default function TrackerPage() {
         />
       )}
 
+      {/* Multi-select action bar — sticky at the bottom while any bills are checked */}
+      {selectedRows.length > 0 && (
+        <div className="tracker-print-hide fixed inset-x-0 bottom-4 z-40 flex justify-center px-4">
+          <div
+            role="toolbar"
+            aria-label="Bulk actions for selected bills"
+            className="flex items-center gap-2 rounded-full border border-border bg-card/95 px-3 py-2 shadow-lg backdrop-blur supports-[backdrop-filter]:bg-card/80"
+          >
+            <span className="px-2 text-sm font-medium tabular-nums">{selectedRows.length} selected</span>
+            <Button
+              size="sm"
+              onClick={handlePaySelected}
+              disabled={bulkBusy || selectedRows.every(r => r.is_skipped || rowIsPaid(r))}
+              className="h-8 gap-1.5"
+            >
+              <CheckCircle2 className="h-4 w-4" />
+              Pay
+            </Button>
+            <Button
+              size="sm"
+              variant="outline"
+              onClick={handleSkipSelected}
+              disabled={bulkBusy || selectedRows.every(r => r.is_skipped)}
+              className="h-8 gap-1.5"
+            >
+              <EyeOff className="h-4 w-4" />
+              Skip
+            </Button>
+            <Button
+              size="sm"
+              variant="ghost"
+              onClick={clearSelection}
+              disabled={bulkBusy}
+              className="h-8 gap-1.5 text-muted-foreground"
+              aria-label="Clear selection"
+            >
+              Clear
+            </Button>
+          </div>
+        </div>
+      )}
+
     </div>
   );
 }