feat: preserve pipe-delimited OR groups in tags DTO

Stop splitting tags on | so that OR-group tokens (e.g. cat|dog) are
forwarded intact to the Universal Booru Wrapper, which applies the
correct engine-specific OR syntax per booru engine.

Pipelines the change through the full stack:
  App → |  (user types 'cat OR dog')
  API  → ['cat|dog']  (kept as OR-group token)
  Wrapper → '{  ~ cat  ~ dog }' (Gelbooru) / '~cat ~dog' (Danbooru/e621)

Author: AlejandroAkbal

src/booru/dto/booru-queries.dto.spec.ts

@@ -31,34 +31,34 @@ describe('booruQueryValuesPostsDTO request handling', () => {
     await app.close()
   })
 
-  it('should rely on request parsing for percent-decoding and split tags by pipe', async () => {
+  it('should rely on request parsing for percent-decoding and preserve comma OR-groups', async () => {
     const response = await app.inject({
       method: 'GET',
-      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=panty_%26_stocking_with_garterbelt%7Crating%3Asafe'
+      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=panty_%26_stocking_with_garterbelt%2Cblue_hair'
     })
 
     const body = JSON.parse(response.body)
 
     expect(response.statusCode).toBe(200)
-    expect(body.tags).toEqual(['panty_&_stocking_with_garterbelt', 'rating:safe'])
+    expect(body.tags).toEqual(['panty_&_stocking_with_garterbelt,blue_hair'])
   })
 
-  it('should normalize repeated tags query params and split each entry', async () => {
+  it('should normalize repeated tags query params and keep each OR-group token intact', async () => {
     const response = await app.inject({
       method: 'GET',
-      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=artist%3Afoo%7Crating%3Asafe&tags=score%3A%3E100'
+      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=artist%3Afoo%2Crating%3Asafe&tags=score%3A%3E100'
     })
 
     const body = JSON.parse(response.body)
 
     expect(response.statusCode).toBe(200)
-    expect(body.tags).toEqual(['artist:foo', 'rating:safe', 'score:>100'])
+    expect(body.tags).toEqual(['artist:foo,rating:safe', 'score:>100'])
   })
 
-  it('should reject empty tags created after pipe splitting', async () => {
+  it('should reject empty tags produced by repeated query params', async () => {
     const response = await app.inject({
       method: 'GET',
-      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=tag1%7C'
+      url: '/dto-test/posts?baseEndpoint=gelbooru.com&tags=tag1&tags='
     })
 
     expect(response.statusCode).toBe(400)

src/booru/dto/booru-queries.dto.ts

@@ -186,9 +186,9 @@ export class booruQueryValuesPostsDTO extends booruQueriesDTO {
       return value
     }
 
-    return (Array.isArray(value) ? value : [value]).flatMap((tag) =>
-      typeof tag === 'string' ? tag.trim().split('|') : [tag]
-    )
+    return (Array.isArray(value) ? value : [value])
+      .map((tag) => (typeof tag === 'string' ? tag : String(tag)))
+      .map((tag) => tag.trim())
   })
   @IsOptional()
   readonly tags: IBooruQueryValues['posts']['tags']