brain-atlas: add pituitary, pineal, gyrus rectus, uvula of vermis

These exist in Z-Anatomy but were dropped by the exporter: the pituitary
(adeno/neurohypophysis) and pineal gland are filed under "Endocrine glands"
outside the Brain collection and also hit the gland/non-neural filter; the gyrus
rectus and uvula of vermis are brain tissue wrongly caught by that filter's
"rectus" / "uvula" substrings.

  - in_scope now keeps anything under the Brain collection before the non-neural
    filter runs (that filter targets cranial-nerve-supplied muscles, not brain
    tissue), rescuing the gyrus rectus (cortex) and uvula of vermis (cerebellum).
  - pituitary + pineal are pulled in and given a diencephalic sibling's collections
    (view-layer + diencephalon category); pituitary lobes share a "Pituitary gland"
    parent. They keep their original Z-Anatomy positions.
  - cochlear nuclei deliberately skipped: Z-Anatomy files them inconsistently
    (only 1 of 4 under Brain) and they are very coarse.

Also add the lateral/medial geniculate bodies to the "Thalamic nuclei" preset.
Model is now 383 named structures.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: itayinbarr

brain-atlas/app.jsx

@@ -33,7 +33,7 @@ const PRESETS = [
       brainstem: ['Red nucleus'],
     } },
   { id: 'thalnuc', label: 'Thalamic nuclei', color: 'var(--c-diencephalon)',   on: ['diencephalon'],                    cortex: 0.10, focus: 'diencephalon',
-    subset: { diencephalon: ['Pulvinar', 'Anterior nuclei of thalamus', 'Mediodorsal nucleus', 'Ventral laterodorsal nucleus', 'Ventral lateroventral nucleus', 'Ventral anterior nucleus', 'Intralaminar and lateral posterior nuclei'] } },
+    subset: { diencephalon: ['Pulvinar', 'Anterior nuclei of thalamus', 'Mediodorsal nucleus', 'Ventral laterodorsal nucleus', 'Ventral lateroventral nucleus', 'Ventral anterior nucleus', 'Intralaminar and lateral posterior nuclei', 'Lateral geniculate body', 'Medial geniculate body'] } },
   { id: 'nerves', label: 'Cranial nerves',   color: 'var(--c-cranial_nerves)', on: ['cranial_nerves','brainstem'],      cortex: 0.12, focus: 'cranial_nerves' },
   { id: 'dura',   label: 'Meninges & dura',  color: 'var(--c-meninges_dura)',  on: ['meninges_dura','veins_sinuses'],   cortex: 0.30, focus: null },
 ];