feat: implement wiki and wiki content management system including database schemas, DTOs, and API endpoints

db/migrations/000016_wiki_content.up.sql

@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS wiki_content (
+    id UUID PRIMARY KEY DEFAULT uuidv7(),
+    wiki_id UUID NOT NULL REFERENCES wikis(id) ON DELETE CASCADE,
+    title TEXT NOT NULL,
+    content TEXT,
+    is_deleted BOOLEAN NOT NULL DEFAULT false,
+    created_at TIMESTAMPTZ DEFAULT now()
+);
+
+CREATE INDEX idx_wiki_content_wiki_id ON wiki_content(wiki_id);
+CREATE INDEX idx_wiki_content_created_at ON wiki_content(created_at DESC);