[Feature] Build a real-time collaborative pool chat/comments feature per group

[grantfox-oss]

Getting Started

1. Fork the repository: https://github.com/JointSave-org/Joint_Save
2. Clone your fork:

   git clone https://github.com/<your-username>/Joint_Save.git
   cd Joint_Save

3. Create a new branch:

   git checkout -b feat/pool-group-chat

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Overview

Members of a savings pool currently have no way to communicate within the app — coordinating deposit timing, discussing target adjustments, or just building trust within the group requires an external channel (WhatsApp, etc.). A lightweight in-app chat per pool would keep coordination inside the platform.

Requirements

• New Supabase table pool_messages (pool_id, sender_address, message, created_at), with RLS restricting read/write to actual members of that pool (verified against pool_members)
• New tab or section on the group detail page: "Discussion"
• Use Supabase Realtime subscriptions for live message delivery without polling
• Basic moderation: message length cap, rate limiting per sender (e.g. max 1 message per 3 seconds) to prevent spam
• Optional: integrate with the existing notification system (feat: add pool event notifications and user email preferences closes issue #68 #85, once merged) so members get notified of new messages if they have that preference enabled

Acceptance Criteria

• Only actual members of a pool can read or send messages in that pool's chat (enforced via RLS, not just UI hiding)
• Messages appear in real time for other connected members without a page refresh
• Rate limiting prevents a single user from spamming the channel
• Chat history persists and loads correctly when revisiting the group page
• Mobile-responsive

[senmalong]

Hello Maintainer,

Please I’d love to take this issue on. I’m a smart contract and full-stack developer with experience across OnlyDust, Drips Waves

My stack includes Rust, Soroban, Cairo, Solidity, and TypeScript. I can deliver a clean, tested, and well-documented solution within 24 hours of assignment.

Happy to start immediately. Thank yOU

[grantfox-oss]

🦊 GrantFox — @senmalong has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #90)
2. Your PR will be reviewed by the JointSave-org maintainers

Good luck! Track your progress on GrantFox.