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) <noreply@anthropic.com>

lib/validations/classes.ts

@@ -0,0 +1,92 @@
+import { z } from 'zod'
+
+// Generic manual payment link only (no live payment integration). Empty
+// string -> null so a cleared field is stored as "no link".
+const paymentLink = z
+  .string()
+  .trim()
+  .max(2000)
+  .optional()
+  .nullable()
+  .transform(v => (v && v !== '' ? v : null))
+  .refine(
+    v => v === null || /^https?:\/\/.+/i.test(v),
+    'Payment link must be an http(s) URL',
+  )
+
+const classCapacity = z
+  .number()
+  .int('Capacity must be a whole number')
+  .positive('Capacity must be at least 1')
+  .max(100000)
+  .optional()
+  .nullable()
+
+const dateTimeString = z.string().min(1, 'A date and time is required').max(40)
+
+export const createClassSchema = z.object({
+  title: z.string().min(1, 'Title is required').max(200),
+  description: z.string().max(5000).optional().nullable(),
+  payment_link: paymentLink,
+  capacity: classCapacity,
+  grants_certification_id: z.string().uuid('Invalid certification ID').optional().nullable(),
+  required_form_id: z.string().uuid('Invalid form ID').optional().nullable(),
+})
+
+export const updateClassSchema = z.object({
+  classId: z.string().uuid('Invalid class ID'),
+  title: z.string().min(1).max(200).optional(),
+  description: z.string().max(5000).optional().nullable(),
+  payment_link: paymentLink,
+  capacity: classCapacity,
+  grants_certification_id: z.string().uuid('Invalid certification ID').optional().nullable(),
+  required_form_id: z.string().uuid('Invalid form ID').optional().nullable(),
+  is_active: z.boolean().optional(),
+})
+
+export const classIdSchema = z.object({
+  classId: z.string().uuid('Invalid class ID'),
+})
+
+export const createSessionSchema = z.object({
+  classId: z.string().uuid('Invalid class ID'),
+  starts_at: dateTimeString,
+  ends_at: z.string().max(40).optional().nullable().transform(v => (v && v !== '' ? v : null)),
+  location: z.string().max(300).optional().nullable(),
+  capacity: classCapacity,
+  notes: z.string().max(5000).optional().nullable(),
+})
+
+export const updateSessionSchema = z.object({
+  sessionId: z.string().uuid('Invalid session ID'),
+  starts_at: dateTimeString.optional(),
+  ends_at: z.string().max(40).optional().nullable().transform(v => (v && v !== '' ? v : null)),
+  location: z.string().max(300).optional().nullable(),
+  capacity: classCapacity,
+  notes: z.string().max(5000).optional().nullable(),
+  status: z.enum(['scheduled', 'cancelled', 'completed']).optional(),
+})
+
+export const sessionIdSchema = z.object({
+  sessionId: z.string().uuid('Invalid session ID'),
+})
+
+export const signUpForClassSchema = z.object({
+  sessionId: z.string().uuid('Invalid session ID'),
+  // Manager-only: sign another member up on their behalf (also bypasses the
+  // required-form gate). Ignored for non-managers.
+  memberId: z.string().uuid('Invalid member ID').optional().nullable(),
+})
+
+export const cancelSignupSchema = z.object({
+  sessionId: z.string().uuid('Invalid session ID'),
+})
+
+export const markAttendanceSchema = z.object({
+  signupId: z.string().uuid('Invalid signup ID'),
+  attended: z.boolean(),
+})
+
+export const listSessionSignupsSchema = z.object({
+  sessionId: z.string().uuid('Invalid session ID'),
+})