feat(content): give the specimen a never-gated core secret

The purge left `gate: never` — the rung no disposition unlocks — demonstrated
nowhere. Duncarrow's Crell chain had taught it; specimen.md only taught `warm`.

Adds secret.specimen-drowned-clerk (secrecy 4, gate: never), so the specimen
now shows an ascending 2 -> 4 chain and a reason `never` exists: the NPC holds
it, but saying it aloud would hang him. Mirrored in the skill's worked example,
which now states the rule — if any rung *should* buy the secret, gate it at
`trusted` instead.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/world-building/SKILL.md

@@ -98,8 +98,9 @@ contradict, and it carries the authoring rules that keep the war in tone
 - **Bible entries:** see `references/schema.md` for the full field-by-field
   contract, the id/namespace/type rules, the secrecy scale, and the knowledge-gate
   model. Match the **structure** of `content/lore/specimen.md` (the synthetic
-  disposition-gate specimen — a guarded-then-warm NPC with one earned reveal) and
-  the **voice** of the canon bodies in `content/lore/cosmology.md`.
+  disposition-gate specimen — a guarded-then-warm NPC with one reveal earned at
+  `warm` and a `never`-gated core no disposition unlocks) and the **voice** of the
+  canon bodies in `content/lore/cosmology.md`.
 - **Hand-authored JSON:** mirror the shape of the existing file in that folder
   (`references/schema.md` documents each). Keep ids stable and lowercase-snake.