feat(content): calling + race blurbs, loaded by ContentDB

Hand-written like items/ — no build-tool namespace needed. Blurbs are content;
mechanics are code, and a test asserts the blurb files carry no hit dice. The
prose is placeholder; swapping it later touches no code, which is what stops the
content BOM from blocking the engine.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QYa9u7Kdxv5gX4AnwWexy8

client/scripts/content/content_db.gd

@@ -8,6 +8,8 @@ var locations: Dictionary = {}
 var npcs: Dictionary = {}
 var quests: Dictionary = {}
 var items: Dictionary = {}
+var callings: Dictionary = {}
+var races: Dictionary = {}
 var canon_entities: Dictionary = {}
 var topics: Dictionary = {}
 
@@ -31,6 +33,8 @@ func load_from(content_root: String) -> void:
 	npcs = _load_dir(world.path_join("npcs"))
 	quests = _load_dir(world.path_join("quests"))
 	items = _load_dir(world.path_join("items"))
+	callings = _load_dir(world.path_join("callings"))
+	races = _load_dir(world.path_join("races"))
 	canon_entities = _load_dir(world.path_join("canon"))
 	topics = _load_dir(world.path_join("topics"))
 
@@ -61,6 +65,10 @@ func has_location(id: String) -> bool: return locations.has(id)
 func has_npc(id: String) -> bool: return npcs.has(id)
 func has_quest(id: String) -> bool: return quests.has(id)
 func has_item(id: String) -> bool: return items.has(id)
+func calling(id: String) -> Dictionary: return callings.get(id, {})
+func race(id: String) -> Dictionary: return races.get(id, {})
+func has_calling(id: String) -> bool: return callings.has(id)
+func has_race(id: String) -> bool: return races.has(id)
 func canon(id: String) -> Dictionary: return canon_entities.get(id, {})
 func topic(id: String) -> Dictionary: return topics.get(id, {})
 func has_canon(id: String) -> bool: return canon_entities.has(id)