Phase 2a: Prisma schema + shared schemas for v1.0 features

- New models: Attachment, Webhook, Notification, SavedView
- New fields: User.notificationPrefs (Json), indexes on Ticket
- post-push.sql manages the tsvector columns + GIN indexes + triggers for
  FTS on Ticket (title/overview/displayId) and Comment (body); Prisma can't
  express these
- package.json scripts: db:push and start:prod now chain `prisma db execute`
  against post-push.sql after `prisma db push`
- db:migrate script removed — project uses push workflow, not migrations
- Shared Zod schemas: attachment (25MB limit + mimetype allowlist), savedView,
  notification (prefs, mark-read, webhook CRUD)
- Shared type additions: Attachment, Notification, SavedView, Webhook,
  PaginatedResponse<T>
- Test fixtures updated for the new User.notificationPrefs column

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

shared/schemas/attachment.ts

@@ -0,0 +1,28 @@
+import { z } from 'zod';
+
+export const ATTACHMENT_MAX_BYTES = 25 * 1024 * 1024;
+
+export const ATTACHMENT_MIME_ALLOWLIST = [
+  'image/png',
+  'image/jpeg',
+  'image/gif',
+  'image/webp',
+  'image/svg+xml',
+  'application/pdf',
+  'application/zip',
+  'application/json',
+  'application/x-yaml',
+  'text/plain',
+  'text/csv',
+  'text/markdown',
+  'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+  'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+  'application/msword',
+  'application/vnd.ms-excel',
+  'application/octet-stream',
+];
+
+export const attachmentTargetSchema = z.object({
+  ticketId: z.string().cuid().optional(),
+  commentId: z.string().cuid().optional(),
+});