Add OTP-first signup and product catalog PDF uploads.

Signup verifies phone before password; existing Meshkee accounts keep their password. Products can attach an optional PDF catalog (max 2MB) via Pars Pack media.

Co-authored-by: Cursor <cursoragent@cursor.com>

database/migrations/099_product_catalog_pdf.sql

@@ -0,0 +1,21 @@
+-- Product catalog PDF (optional document on products) + media_type.document
+
+DO $$ BEGIN
+  ALTER TYPE media_type ADD VALUE IF NOT EXISTS 'document';
+EXCEPTION
+  WHEN duplicate_object THEN NULL;
+END $$;
+
+ALTER TABLE products
+  ADD COLUMN IF NOT EXISTS catalog_media_id BIGINT NULL;
+
+DO $$ BEGIN
+  ALTER TABLE products
+    ADD CONSTRAINT products_catalog_media_id_fkey
+    FOREIGN KEY (catalog_media_id) REFERENCES media (id) ON UPDATE NO ACTION;
+EXCEPTION
+  WHEN duplicate_object THEN NULL;
+END $$;
+
+CREATE INDEX IF NOT EXISTS idx_products_catalog_media_id
+  ON products (catalog_media_id);