feat(cloud-agent-next): add latest assistant message endpoint

[kilo-code-bot]

Summary

• Adds a protected getLatestAssistantMessage tRPC procedure for user-token access to a session's latest assistant response.
• Queries the session Durable Object SQLite events for the latest root-session assistant message.updated by sortable message ID and returns its current parts.
• Adds schema, RPC, unit, and integration coverage for ownership, missing sessions, no-message sessions, and child-session exclusion.

Verification

• pnpm -w exec oxfmt services/cloud-agent-next/src services/cloud-agent-next/test
• pnpm -w exec oxfmt --list-different services/cloud-agent-next/src services/cloud-agent-next/test
• pnpm --filter cloud-agent-next exec vitest run src/router.test.ts
• pnpm --filter cloud-agent-next run test:integration -- test/integration/session/events.test.ts
• pnpm --filter cloud-agent-next run typecheck
• pnpm --filter cloud-agent-next run lint
• pnpm -w exec oxlint --config .oxlintrc.json services/cloud-agent-next/test/integration/session/events.test.ts

Visual Changes

N/A

Reviewer Notes

• Latest assistant lookup requires metadata.kiloSessionId and filters message.updated rows to that root Kilo session; child/subagent assistant messages are intentionally excluded.
• Verification emitted the existing Node engine warning because this environment uses Node v20.20.2 while the repo wants >=24 <25.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (2 files)

• services/cloud-agent-next/src/session/queries/events.ts
• services/cloud-agent-next/test/integration/session/events.test.ts

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_{Reviewed by gpt-5.4-20260305 · 800,909 tokens}