refactor: routing logic moved from frontend to backend

[Ragini-Microsoft]

Purpose

This pull request refactors the frontend API layer and introduces a new backend routing service to centralize and standardize message intent detection and routing logic. The changes simplify the frontend API surface, unify message handling, and move previously frontend-based routing logic into a dedicated backend service. Additionally, the backend is now better equipped for intent-based message processing, and related tests have been updated accordingly.

Frontend API Refactor and Unification:

• Consolidated multiple frontend API functions (parseBrief, confirmBrief, selectProducts, streamChat, etc.) into a single sendMessage function for sending messages/actions to the /api/chat endpoint, and introduced a unified MessageRequest/MessageResponse type. This streamlines the frontend-backend communication and reduces duplicated logic. [1] [2]
• Updated the streamGenerateContent and content generation polling functions to use a single GenerateRequest payload, improving consistency and maintainability.
• Added a new pollTaskStatus function to poll for task completion (including image regeneration), replacing the previous streaming implementation for image regeneration.

Backend Routing Service Introduction:

• Added a new routing_service.py module that encapsulates message classification and intent detection logic. This service mirrors and replaces the routing previously done in the frontend and provides a clear, testable interface for determining user intent based on message content and conversation state.

Test Updates:

• Updated tests to use the new unified /api/chat endpoint and to check for correct intent routing (e.g., PARSE_BRIEF intent for title generation). Adjusted mocks and assertions to match the new backend logic and API surface. [1] [2] [3] [4]

These changes collectively modernize the codebase by centralizing routing logic, simplifying the frontend API, and improving maintainability and testability.

Most important changes:

Frontend API Refactor:

• Unified multiple message-related API calls into a single sendMessage function and introduced MessageRequest/MessageResponse types, simplifying frontend-backend communication. [1] [2]
• Changed content generation and polling functions to use a standardized GenerateRequest payload and added pollTaskStatus for task polling. [1] [2]

Backend Routing Service:

• Introduced routing_service.py, a backend service for message intent classification and routing, moving logic from the frontend to the backend for better maintainability and testability.

Test Adjustments:

• Updated tests to use the new /api/chat endpoint, reflecting the new routing and intent detection logic, and adjusted mocks accordingly. [1] [2] [3] [4]

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.