Expand repair tests to 43 cases, fix default status to new

Comprehensive test coverage for repairs: full status lifecycle (new →
picked_up), in_transit branch, pending_parts round-trip, delivered
alternate ending, reopen cancelled, validation errors, search by
instrument, filter by status and isBatch, notes CRUD with visibility
and status capture, service templates CRUD with soft-delete, signed
URL generation and access. Migration to set column default to new.
107 total API tests passing.

packages/backend/src/db/migrations/0020_repair_default_new.sql

@@ -0,0 +1 @@
+ALTER TABLE "repair_ticket" ALTER COLUMN "status" SET DEFAULT 'new';