refactor(debt): resolve all 10 technical debt items from audit

fix: resolve login 400 — auto-resolve organizationId from email when omitted

style: standardize frontend imports using @/ alias

fix: resolve chart dimension warnings and block default-org-id ghost calls

fix: ensure JWT token is consistently injected in organization fetch calls

feat: migrate to multi-tenant SaaS architecture with JWT auth and BullMQ notifications

feat: B2B SaaS Multi-tenant architecture & Tech Debt Resolution