feat(doctors): search every specialty a doctor has, and expose the tree

`GET /api/v1/doctors` could not answer either question the public search box
asks. Typing a specialty name returned nothing, because `name` only matched
`d.name`. And `specialty_id` matched one id exactly, so a parent group only
found doctors who happened to carry the parent — which they usually do, but
only as a side effect of `expandWithAncestors` running on save. A doctor
imported through any other path has no denormalised parent, and a search
guarantee resting on a save-time side effect is not a guarantee.

`expandWithDescendants` mirrors the existing ancestor walk over the same cached
parentMap, so no extra query. It deliberately keeps unknown ids instead of
dropping them like its mirror does: the result feeds an `IN (...)`, and an empty
array turns the filter into a no-op that returns every doctor — an unknown id
must mean "nothing", never "everything".

Both specialty filters use their own EXISTS alias rather than the shared `s`
join. Two conditions on one alias force a single join row to satisfy both, so a
doctor filtered by specialty A while searching the name of specialty B was
silently dropped. Verified by reverting to the shared alias and watching
testFilterOnOneSpecialtyWhileSearchingTheNameOfAnother fail.

toListArray now carries specialties[].parent_id so a client can tell the main
specialty from a sub-specialty instead of printing all of them. It is a string,
matching toDetailArray and the sibling `id` key — one concept should not have
two types across two endpoints. Reading the id off the parent proxy costs no
query; measured 6→11 queries with four more doctors both with and without the
field. That growth is a pre-existing N+1 (findWithFilters does not fetch-join
specialties, unlike findByClinic) and is left untouched here.

Also drops the phantom `search` parameter from the OpenAPI annotation — it was
advertised but never read, so a client sending it got an unfiltered list — and
documents the six live parameters that were missing.

Note for deploy: DoctorRepository gained a constructor argument, so a stale
container fails with ArgumentCountError until cache:clear runs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/Doctor/Entity/Doctor.php

@@ -575,10 +575,17 @@ class Doctor
             'gender'        => $this->gender,
             'degree'        => $this->degree,
             'img'           => $this->images ?? [],
+            // parent_id لازم است تا کلاینت «تخصص اصلی» را از زیرتخصص تشخیص دهد؛
+            // بدون آن کارت پزشک ناچار است همهٔ نام‌ها را پشت‌سرهم چاپ کند.
+            //
+            // رشته است نه عدد، تا با toDetailArray هم‌شکل بماند — کلاینت نباید برای
+            // یک مفهوم دو قاعدهٔ نوع بنویسد. خواندنِ شناسه از proxy والد کوئری اضافه
+            // نمی‌زند؛ شناسه از قبل معلوم است.
             'specialties'   => array_map(fn(Specialty $s) => [
                 'uuid' => $s->getUuid(),
                 'id' => (string) $s->getId(),
                 'name' => $s->getName(),
+                'parent_id' => $s->getParent()?->getId() !== null ? (string) $s->getParent()->getId() : null,
             ], $this->specialties->toArray()),
             'satisfaction'  => $this->hasPublicRating() ? (string) $this->doctorRatePercentage : null,
             'point'         => $this->hasPublicRating() ? (string) $this->doctorRate : null,