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

backend/migrations/20260602_03_drop_documents_file_metadata.sql

@@ -0,0 +1,51 @@
+-- Migration date: 2026-06-02
+
+-- Destructive follow-up migration: remove legacy document-level file metadata.
+--
+-- Run this only after application code writes file_type, size_bytes,
+-- and page_count to document_versions and reads those values
+-- from the active version.
+
+DO $$
+DECLARE
+  documents_file_metadata_count integer;
+BEGIN
+  SELECT count(*)
+  INTO documents_file_metadata_count
+  FROM information_schema.columns
+  WHERE table_schema = 'public'
+    AND table_name = 'documents'
+    AND column_name IN (
+      'file_type',
+      'size_bytes',
+      'page_count'
+    );
+
+  IF documents_file_metadata_count = 3 THEN
+    ALTER TABLE public.document_versions
+      ADD COLUMN IF NOT EXISTS file_type text,
+      ADD COLUMN IF NOT EXISTS size_bytes integer,
+      ADD COLUMN IF NOT EXISTS page_count integer;
+
+    UPDATE public.document_versions dv
+    SET
+      file_type = COALESCE(NULLIF(btrim(dv.file_type), ''), d.file_type),
+      size_bytes = COALESCE(dv.size_bytes, d.size_bytes),
+      page_count = COALESCE(dv.page_count, d.page_count)
+    FROM public.documents d
+    WHERE dv.document_id = d.id
+      AND (
+        dv.file_type IS NULL
+        OR btrim(dv.file_type) = ''
+        OR dv.size_bytes IS NULL
+        OR dv.page_count IS NULL
+      );
+  END IF;
+
+  IF documents_file_metadata_count > 0 THEN
+    ALTER TABLE public.documents
+      DROP COLUMN IF EXISTS file_type,
+      DROP COLUMN IF EXISTS size_bytes,
+      DROP COLUMN IF EXISTS page_count;
+  END IF;
+END $$;