feat(rules): manual-only rules as one-click quick actions on selected transactions

A rule flagged manual_only never runs in the apply-all pass; instead it shows
as a button in the transactions bulk bar and applies its actions to the current
selection (conditions ignored — the selection is the condition). Recorded as a
rule_apply_run, so it reverts from Rules -> Apply History like any other run.

Motivation: tagging Home + splitting 50/50 with Sonu was two bulk actions every
time. Now it is one click, and any other combo can be defined the same way.

Extracts the action-application and snapshot logic from the apply route into
src/lib/rule-actions.ts so both callers share one implementation — splits upsert
rather than delete+reinsert, so settled flags survive.

src/app/transactions/page.tsx

@@ -2,7 +2,7 @@
 
 import { useState, useCallback, useRef, useEffect, Suspense } from "react";
 import { useSearchParams } from "next/navigation";
-import { useTransactions, useBanks, useUpdateTransaction, useBulkAction, useTags, useStatement, useCreateRule, useParticipants, useRecordPayment, useCurrentUser, useTrips, useAssignTransactionsToTrip } from "@/lib/hooks";
+import { useTransactions, useBanks, useUpdateTransaction, useBulkAction, useTags, useStatement, useCreateRule, useParticipants, useRecordPayment, useCurrentUser, useTrips, useAssignTransactionsToTrip, useRules } from "@/lib/hooks";
 import { CATEGORIES, formatCategory } from "@/lib/categories";
 import { SplitModal } from "@/components/split-modal";
 import { TagPicker } from "@/components/tag-picker";
@@ -10,6 +10,7 @@ import { AddTransactionModal } from "@/components/add-transaction-modal";
 import { EditTransactionModal } from "@/components/edit-transaction-modal";
 import { CsvImportModal } from "@/components/csv-import-modal";
 import type { TransactionRow } from "@/lib/queries";
+import type { RuleRow } from "@/lib/hooks";
 
 function formatDate(d: string) {
   return new Date(d).toLocaleDateString("en-AU", {
@@ -43,6 +44,28 @@ const TYPE_OPTIONS = [
   "debit", "credit", "payment", "refund", "fee", "interest", "transfer",
 ].map((t) => ({ value: t, label: t }));
 
+/** Tooltip text for a quick-action button: what the rule will actually do. */
+function describeActions(
+  actions: RuleRow["actions"],
+  tags: { id: number; name: string }[] = [],
+  participants: { id: number; name: string }[] = []
+): string {
+  const parts: string[] = [];
+  if (actions.set_category) parts.push(`category → ${formatCategory(actions.set_category)}`);
+  if (actions.set_merchant) parts.push(`merchant → ${actions.set_merchant}`);
+  if (actions.add_tag_ids?.length) {
+    const names = actions.add_tag_ids.map((id) => tags.find((t) => t.id === id)?.name ?? `tag#${id}`);
+    parts.push(`tag: ${names.join(", ")}`);
+  }
+  if (actions.apply_split?.length) {
+    const shares = actions.apply_split.map(
+      (s) => `${participants.find((p) => p.id === s.participant_id)?.name ?? `#${s.participant_id}`} ${s.share_percent}%`
+    );
+    parts.push(`split: ${shares.join(" / ")}`);
+  }
+  return parts.join(" · ") || "no actions";
+}
+
 function TypeBadge({ type }: { type: string }) {
   return (
     <span className={`px-2 py-0.5 rounded text-xs font-medium ${TYPE_COLORS[type] || "bg-zinc-800 text-zinc-400"}`}>
@@ -528,6 +551,10 @@ function TransactionsContent() {
   const bulkAction = useBulkAction();
   const { data: trips = [] } = useTrips();
   const assignToTrip = useAssignTransactionsToTrip();
+  const { data: allRules = [] } = useRules();
+  const { data: participants = [] } = useParticipants();
+  const quickActions = allRules.filter((r) => r.manual_only);
+  const [quickResult, setQuickResult] = useState<string | null>(null);
 
   const toggleSelect = useCallback((id: number) => {
     setSelected((prev) => {
@@ -787,6 +814,32 @@ function TransactionsContent() {
           >
             {bulkTripId === "remove" ? "Remove" : "Assign"}
           </button>
+          {quickActions.length > 0 && (
+            <div className="flex items-center gap-2 pl-3 ml-1 border-l border-zinc-700">
+              {quickActions.map((rule) => (
+                <button
+                  key={rule.id}
+                  disabled={bulkAction.isPending}
+                  title={describeActions(rule.actions, tags, participants)}
+                  onClick={() => {
+                    const count = selected.size;
+                    bulkAction.mutate(
+                      { action: "apply_rule", ids: Array.from(selected), rule_id: rule.id },
+                      {
+                        onSuccess: () => {
+                          setSelected(new Set());
+                          setQuickResult(`${rule.name} applied to ${count} transaction${count !== 1 ? "s" : ""}`);
+                        },
+                      }
+                    );
+                  }}
+                  className="px-3 py-1 bg-amber-700/80 hover:bg-amber-600 disabled:opacity-50 rounded text-sm"
+                >
+                  {rule.name}
+                </button>
+              ))}
+            </div>
+          )}
           <button
             onClick={() => setSelected(new Set())}
             className="px-3 py-1 text-zinc-400 hover:text-white text-sm"
@@ -796,6 +849,18 @@ function TransactionsContent() {
         </div>
       )}
 
+      {quickResult && (
+        <div className="flex items-center gap-3 mb-3 px-3 py-2 bg-emerald-900/30 border border-emerald-700 rounded text-sm text-emerald-200">
+          <span>{quickResult}</span>
+          <a href="/rules" className="text-emerald-400 hover:text-emerald-300 underline">
+            undo from Rules → Apply History
+          </a>
+          <button onClick={() => setQuickResult(null)} className="ml-auto text-zinc-400 hover:text-white">
+            dismiss
+          </button>
+        </div>
+      )}
+
       {/* Table */}
       <div className="overflow-x-auto border border-zinc-800 rounded-lg">
         <table className="w-full text-sm min-w-[900px]">