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.

prisma/schema.prisma

@@ -98,15 +98,16 @@ model transaction_tags {
 }
 
 model rules {
-  id         Int      @id @default(autoincrement())
-  owner_id   Int
-  name       String
-  conditions Json     @default("[]")
-  actions    Json     @default("{}")
-  enabled    Boolean  @default(true)
-  priority   Int      @default(0)
-  created_at DateTime @default(now())
-  updated_at DateTime @default(now()) @updatedAt
+  id          Int     @id @default(autoincrement())
+  owner_id    Int
+  name        String
+  conditions  Json    @default("[]")
+  actions     Json    @default("{}")
+  enabled     Boolean @default(true)
+  manual_only Boolean @default(false)
+  priority    Int      @default(0)
+  created_at  DateTime @default(now())
+  updated_at  DateTime @default(now()) @updatedAt
 }
 
 model budgets {