Migrate the channel state responses to the generated channel state models

[gpunto]

Goal

Parse the channel state returned by queryChannels, queryChannel and grouped channels with the generated models.

Part of AND-1291

Implementation

• Point the three query endpoints at the generated QueryChannelsResponse, ChannelStateResponse and GroupedQueryChannelsResponse, and delete the hand-written QueryChannelsResponse and QueryGroupedChannelsResponse.
• Map the channel state with the generated channel and message mappers. A state without a channel fails the call instead of throwing.
• Map pending messages from the generated PendingMessageResponse. Their metadata is server-side only and never sent to client-side callers, so it stays empty as before.
• The update, delete, truncate and member endpoints still parse the hand-written envelope; they move in a follow-up.

Testing

E2E needs the mock server to send duration on single channel queries, as the backend does (mock server PR to follow).

MoshiChatApiTest covers a channel state with every field set, the single-channel conversion, and a state without a channel. Before this, a recorded channel state was mapped through both the old and the new path and produced the same Channel, including pending messages, hidden state, watchers and push preferences.

On a device: queried a channel with pinned, quoted and thread messages, a reaction, a live location, a draft, reads and a push preference through queryChannel and queryChannels. Every field was set and both calls agreed. Hiding the channel returned the hidden flag and date, and offset pagination returned non-overlapping pages.

🤖 Generated with Claude Code

[github-actions]

PR checklist ✅

All required conditions are satisfied:

• Title length is OK (or ignored by label).
• At least one pr: label exists.
• Sections ### Goal, ### Implementation, and ### Testing are filled, or the PR is bot-authored.
• An issue is linked (Linear ticket or GitHub issue), or the PR is bot-authored.

🎉 Great job! This PR is ready for review.

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-chat-android-client	6.17 MB	6.18 MB	0.01 MB	🟢
stream-chat-android-ui-components	11.48 MB	11.48 MB	0.01 MB	🟢
stream-chat-android-compose	13.14 MB	13.15 MB	0.01 MB	🟢

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
97.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud