feat: add cloud conversation observability fields

[juanmichelini]

Summary

• add observability_metadata, observability_tags, and observability_span_name to CloudConversationStartRequest
• export the observability metadata helper types
• cover CloudClient.createConversation forwarding these fields to /api/v1/app-conversations

Context

Companion client typing update for OpenHands/sandbox-server#3, which exposes these fields on POST /api/v1/app-conversations after the Agent Canvas/app-server migration.

Related docs: OpenHands/docs#670.

Testing

• npm ci (runs build via prepare)
• npm test -- --runTestsByPath src/tests/api-clients.test.ts

[github-actions]

Endpoint audit

⚠️ 7 actionable Agent Server contract divergence(s) · report-only

Contract: pinned release artifact

Category	Count
Actionable client-only calls	0
Actionable server-only operations	7
Documented non-divergences	12
Agent Server contract operations	117
Audited handwritten client endpoints	118

Actionable client-only calls (0)

none

Actionable server-only operations (7)

• GET /api/conversations/{}/events
• GET /api/file/archive
• GET /api/git/commits
• GET /api/git/commits/{}/changes
• GET /api/init
• POST /api/conversations/{}/load_plugin
• POST /api/init

Documented non-divergences (12)

Client calls intentionally absent from the filtered contract (10)

• 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

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