feat: add unaccent support for accent-insensitive search (#1402)

- Add PostgreSQL unaccent and pg_trgm extensions
- Create immutable f_unaccent wrapper function for performance
- Update all search queries to use f_unaccent for accent-insensitive matching
- Add 1MB limit to tsvector content to prevent errors on large documents
- Update full-text search trigger to use f_unaccent
- Fix MultiSelect client-side filtering to show server results properly

apps/server/src/core/workspace/services/workspace-invitation.service.ts

@@ -8,6 +8,7 @@ import { AcceptInviteDto, InviteUserDto } from '../dto/invitation.dto';
 import { UserRepo } from '@docmost/db/repos/user/user.repo';
 import { InjectKysely } from 'nestjs-kysely';
 import { KyselyDB } from '@docmost/db/types/kysely.types';
+import { sql } from 'kysely';
 import { executeTx } from '@docmost/db/utils';
 import {
   Group,
@@ -55,7 +56,11 @@ export class WorkspaceInvitationService {
 
     if (pagination.query) {
       query = query.where((eb) =>
-        eb('email', 'ilike', `%${pagination.query}%`),
+        eb(
+          sql`email`,
+          'ilike',
+          sql`f_unaccent(${'%' + pagination.query + '%'})`,
+        ),
       );
     }