Fix OAuth on reverse proxy (HuggingFace): trust proxy, secure cookies, error display

feat: add Email Senders page, replace Reports with Coming Soon, remove AI references

fix: use Express 5 path-to-regexp syntax for SPA fallback route

feat: add Docker deployment for HuggingFace Spaces

feat: add Excel export, filters, search, match accuracy, journal page, and email viewer improvements

Initial commit — ICC Interac Manager full-stack app