feat:Add authentication, location tracking, translations, PDF export, and feedback flow

This MR enhances the Hyderabad Civic Complaint Assistant with a more complete citizen complaint workflow.

Changes Included

Added user registration and login with SQLite-backed authentication. Added browser-based location detection and reverse geocoding. Improved complaint classification, department routing, and complaint history storage. Added Hindi and Telugu translation support for generated complaints. Added PDF export support for original and translated complaints. Added user feedback collection. Updated README, user manual, requirements, and environment examples. Fixed linting/formatting issues and resolved merge conflicts across app modules.