Concepts docs: RAG / semantic search architecture

[codebestia]

Write apps/ai_agent/docs/concepts-rag-search-architecture.md explaining how /index/message and /search together form a retrieval pipeline: what gets embedded, how OpenAI is used (embedding model, and separately the chat model), and how this pipeline is meant to be consumed by callers.

Acceptance criteria:

• The indexing pipeline (message text → embedding → Weaviate storage) is documented step by step
• The retrieval pipeline (query → embedding → Weaviate similarity search → results) is documented step by step
• Explicitly documents whether/how retrieved results currently feed back into any other endpoint's LLM prompt — if no integration exists yet, the doc states that plainly

[flexocode442]

@flexocode442 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello Maintainer, I'd like to work on this issue. I have experience with blockchain development and state management, and I can implement this. Please consider assigning it to me.
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ℹ️ Repo Maintainers: To accept this application, review their application or assign @flexocode442 to this issue.

[samkay-ops]

@samkay-ops has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi team,
I'm applying to work on this issue.
I have strong experience with TypeScript, NestJS, and Soroban smart contracts. I will deliver clean, tested code following the acceptance criteria.
Ready to start immediately.
Best regards,
samkay-ops

ℹ️ Repo Maintainers: To accept this application, review their application or assign @samkay-ops to this issue.

[lockoabosede8-byte]

@lockoabosede8-byte has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I would like to work on this issue.

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[Netty-kun]

@Netty-kun has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello Maintainer, I'd like to take this issue. I've reviewed the requirements and have experience with similar implementations. If assigned, I'll begin immediately and work toward delivering a clean, production-ready PR as quickly as possible.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Netty-kun to this issue.

[pleasureiliya69-ops]

@pleasureiliya69-ops has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I would like to work on this issue

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[drips-wave]

Congratulations, @flexocode442! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @flexocode442: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

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