refactor: add table primitive and migrations by date; feat: add mcp connectors

backend/migrations/20260513_projects_shared_with_jsonb.sql

@@ -0,0 +1,36 @@
+-- Migration date: 2026-05-13
+
+-- Migration: convert projects.shared_with from text[] to jsonb.
+-- tabular_reviews.shared_with is already jsonb and is intentionally untouched.
+
+-- Only convert while shared_with is still text[]. Re-running the type change
+-- over an already-jsonb column is unnecessary and the guard keeps it a no-op.
+do $$
+begin
+  if (
+    select data_type
+    from information_schema.columns
+    where table_schema = 'public'
+      and table_name = 'projects'
+      and column_name = 'shared_with'
+  ) = 'ARRAY' then
+    alter table public.projects
+        alter column shared_with drop default;
+
+    alter table public.projects
+        alter column shared_with type jsonb
+        using case
+            when shared_with is null then '[]'::jsonb
+            else to_jsonb(shared_with)
+        end;
+  end if;
+end $$;
+
+alter table public.projects
+    alter column shared_with set default '[]'::jsonb;
+
+alter table public.projects
+    alter column shared_with set not null;
+
+create index if not exists projects_shared_with_idx
+    on public.projects using gin (shared_with);