docs(plans): add shared session history plan

[kilo-code-bot]

Summary

• Adds a discussion plan for public shared-session chat history.
• Recommends a lightweight /s/{public_id} landing page with a client-rendered read-only "View in Cloud Agent" route.
• Calls out client-side React Query fetching from a public/sanitized session-ingest endpoint, shared renderer reuse via CloudAgentTranscript/MessageList, and security/revocation considerations.

Verification

Not run (planning document only).

Visual Changes

N/A

Reviewer Notes

Planning-only PR.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• .plans/shared-session-chat-history-plan.md

---

_{Reviewed by gpt-5.4-20260305 · 148,551 tokens}