[feat] add initial database schema with tables, triggers, and views

database/main/culture_trait.sql

@@ -0,0 +1,21 @@
+create table culture_trait
+(
+    culture_id  INTEGER not null
+        references culture
+            on delete cascade,
+    trait_id    INTEGER not null
+        references trait
+            on delete restrict,
+    tag         TEXT    not null,
+    level       INTEGER,
+    param_value TEXT,
+    primary key (culture_id, trait_id, tag),
+    check (tag IN ('TYPISCH', 'EMPFOHLEN'))
+);
+
+create index idx_culture_trait_trait
+    on culture_trait (trait_id);
+
+create index idx_culture_trait_trait2
+    on culture_trait (trait_id);
+