Bug/93503 improve progressive rendering

[dshire]

Please test together with PRs in Cognigy repo and chat-components repo (Cognigy/chat-components#116).

Follow the PR description here: https://cognigy.visualstudio.com/Cognigy.AI/_git/cognigy/pullrequest/41098

before we merge this, we need to first merge and publish and install the chat-component changes here

[sushmi21]

The animation works as mentioned in the success criteria

[sushmi21]

Code changes look good to me

[vj-venkatesan]

I added a comment in chat components linking here

Cognigy/chat-components#116 (review)

[Copilot]

Pull Request Overview

This PR addresses Bug/93503 by improving progressive rendering and updating related state management.

• Restructures the messages state from an array to an object containing messageHistory and visibleOutputMessages.
• Updates reducers, middlewares, and components to handle the new state structure and streaming message finish reasons.
• Adjusts Cypress commands and compatibility with legacy message formats.

Reviewed Changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/webchat/store/reducer.ts	Refactors messages state and updates SET_PREV_STATE to use the new messages structure.
src/webchat/store/previous-conversations/previous-conversations-middleware.ts	Updates messages access to use messageHistory.
src/webchat/store/options/options-middleware.ts	Fixes backward compatibility for persisted messages by extracting messageHistory.
src/webchat/store/messages/message-reducer.ts	Updates the reducer for adding and animating messages, including support for finishReason and message collation.
src/webchat/store/messages/message-middleware.ts	Adjusts middleware to work with the new messages structure.
src/webchat/store/messages/helper.ts	Adds helper function for determining if a message is animated.
src/webchat/store/autoinject/autoinject-middleware.ts	Changes messages access to use messageHistory for filtering.
src/webchat/components/ConnectedWebchatUI.tsx	Connects visibleOutputMessages from state and updates props accordingly.
src/webchat-ui/components/WebchatUI.tsx	Filters visible messages based on progressive rendering and visibleOutputMessages.
src/common/interfaces/message.ts	Extends IStreamingMessage to include finishReason.
cypress/support/commands.ts	Updates state access for messages in test commands.

Files not reviewed (1)

• package.json: Language not supported

Comments suppressed due to low confidence (3)

src/webchat/store/reducer.ts:81

• Resetting visibleOutputMessages to an empty array in the SET_PREV_STATE action may unintentionally discard previously stored visible message IDs. Consider preserving the existing visibleOutputMessages if appropriate.

const visibleOutputMessages = [];

src/webchat/store/messages/message-reducer.ts:109

• [nitpick] The variable 'newMessageId' is re-declared inside the block, shadowing an outer variable. Consider renaming the inner variable or restructuring the code to avoid shadowing.

const newMessageId = generateRandomId();

src/webchat/store/messages/message-reducer.ts:90

• [nitpick] Consider using consistent camelCase naming for clarity, for example 'isProgressiveMessageRenderingEnabled' instead of 'isprogressiveMessageRenderingEnabled'.

(!isOutputCollationEnabled && !isprogressiveMessageRenderingEnabled) ||