Q27: knowledge corrections keep a revision history

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main/database/migrations/064-knowledge-revisions.ts

@@ -0,0 +1,24 @@
+export const knowledgeRevisionsSchema = `
+  create table if not exists knowledge_revisions (
+    id text primary key,
+    org_id text not null references organizations(id) on delete cascade,
+    entry_id text not null,
+    revision integer not null,
+    topic text not null,
+    category text not null,
+    content text not null,
+    importance text not null,
+    changed_by_type text not null,
+    changed_by_id text,
+    reason text not null,
+    created_at text not null,
+    unique (entry_id, revision)
+  );
+
+  insert into knowledge_revisions(id, org_id, entry_id, revision, topic, category, content, importance, changed_by_type, changed_by_id, reason, created_at)
+  select 'knr_' || lower(hex(randomblob(16))), org_id, id, 1, topic, category, content, importance, source_type, source_id, 'created', created_at
+  from knowledge_entries;
+
+  insert into schema_migrations(version, name, applied_at)
+  values (64, 'knowledge_revisions', datetime('now'));
+`;