refactor(validations): split lib/validations.ts into a barrel'd folder (slice 1)

1141-line lib/validations.ts → lib/validations/<feature>.ts + primitives.ts +
an index.ts barrel. '@/lib/validations' now resolves to the barrel, so all 40
importers are untouched. Every one of the 143 exports is preserved verbatim
(verified by symbol-diff); schemas moved unchanged. tsc 0, 635 tests green.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

lib/validations/import.ts

@@ -0,0 +1,26 @@
+import { z } from 'zod'
+import { emailField, flexibleDateTime } from './primitives'
+
+const importEmail = emailField('Invalid email')
+
+export const importMembersSchema = z.array(
+  z.object({
+    display_name: z.string().min(1, 'Name required').max(100),
+    email: importEmail,
+    phone: z.string().max(20).optional().nullable(),
+    tier: z.enum(['plus', 'basic', 'associate']).optional(),
+    joined_at: flexibleDateTime().optional(),
+    last_paid_at: flexibleDateTime().optional(),
+    has_card_access: z.boolean().optional(),
+  }),
+).max(5000)
+
+export const importPaymentsCsvSchema = z.array(
+  z.object({
+    platform: z.enum(['paypal', 'zeffy', 'venmo', 'cash']),
+    amount: z.number().finite().positive('Amount must be positive').max(10_000_000),
+    from_identifier: z.string().min(1, 'Payer required').max(200),
+    from_note: z.string().max(500).optional().nullable(),
+    transaction_date: flexibleDateTime().optional(),
+  }),
+).max(10000)