feat: expose custom title generation prompts

[DevinVinson]

• A human has tested these changes.

---

Why

The TypeScript client needs to expose the optional custom title-generation prompt accepted by the Agent Server in OpenHands/software-agent-sdk#4564.

Summary

• Add prompt?: string to CreateConversationPayload, matching the final SDK contract.
• Add a static contract assertion for the optional field.

Issue Number

Closes #350

How to Test

Run:

• npm run lint
• npm run build
• npm run test:coverage
• npm run format:check

All completed successfully; 18 suites and 308 tests passed. ESLint reported only the repository's 17 existing warnings and no errors.

Video/Screenshots

Not applicable; this is a type-only client contract change.

Type

• Bug fix
• Feature
• Refactor
• Breaking change
• Docs / chore

Notes

• Depends on OpenHands/software-agent-sdk#4564.
• The generated OpenAPI contract remains pinned to a released Agent Server version and should be regenerated after the SDK field is released.

[github-actions]

Endpoint audit

⚠️ 12 actionable Agent Server contract divergence(s) · report-only

Contract: pinned release artifact

Category	Count
Actionable client-only calls	0
Actionable server-only operations	12
Documented non-divergences	13
Agent Server contract operations	123
Audited handwritten client endpoints	119

Actionable client-only calls (0)

none

Actionable server-only operations (12)

• DELETE /api/llm/provider-connections/{}
• GET /api/conversations/{}/events
• GET /api/file/archive
• GET /api/git/commits
• GET /api/git/commits/{}/changes
• GET /api/init
• GET /api/llm/provider-connections
• PATCH /api/llm/provider-connections/{}
• POST /api/conversations/{}/load_plugin
• POST /api/file/create_directory
• POST /api/init
• POST /api/llm/provider-connections

Documented non-divergences (13)

Client calls intentionally absent from the filtered contract (11)

• GET /
• GET /alive
• GET /health
• GET /ready
• GET /server_info

Reason: Operational Agent Server endpoints intentionally excluded from the filtered public release artifact.
Owner: OpenHands runtime maintainers

• DELETE /api/meta-profiles/{}
• GET /api/meta-profiles
• GET /api/meta-profiles/{}
• POST /api/meta-profiles/{}
• POST /api/meta-profiles/{}/activate

Reason: Client-ahead API stacked on the pending Agent Server meta-profiles implementation.
Owner: OpenHands SDK maintainers
Tracking: OpenHands/software-agent-sdk#3744

• POST /api/profiles/{}/validate

Reason: Client-ahead API stacked on the pending Agent Server pre-flight LLM validation endpoint.
Owner: OpenHands TypeScript client maintainers
Tracking: OpenHands/software-agent-sdk#4422

Server operations covered by an exposed browser URL (2)

• GET /api/conversations/{}/workspace
• GET /api/conversations/{}/workspace/{}

Reason: RemoteWorkspace.startWorkspaceSession exposes these authenticated URLs for browser iframe and file requests; they are not HttpClient method calls.
Owner: OpenHands TypeScript client maintainers

[all-hands-bot]

👋 This PR needs a couple of things fixed before OpenHands can review it:

• the PR description's HUMAN: section needs at least 20 characters describing what you tested, not just the template placeholder

Push an update once this is addressed and this check re-runs automatically.

This is an automated check - no AI was used to generate this comment.