fix: configure timeout for A2A agents

[TannyXie]

Summary

• add timeout_seconds storage for external A2A agents
• add settings API and frontend timeout input
• use the saved timeout for normal and streaming A2A calls

Validation

• python -m pytest test/backend/services/test_a2a_client_service.py test/backend/utils/test_a2a_http_client.py test/sdk/core/agents/test_a2a_agent_proxy.py -q
• npm run type-check

[Copilot]

Pull request overview

This PR adds per-external-agent request timeout configuration for A2A client agents, persisting the value in the backend database and exposing it through a new settings API that the frontend uses to let users edit the timeout. The stored timeout is then applied to both standard and streaming outbound A2A calls.

Changes:

• Add timeout_seconds persistence for external A2A agents (DB migration + ORM model + DB access layer).
• Introduce a backend settings endpoint to update per-agent call settings (currently timeout).
• Update frontend A2A discovery UI/service layer to edit and save timeout, and apply it when calling external agents (normal + streaming), including agent config creation.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
frontend/services/api.ts	Adds the /settings endpoint URL builder for A2A external agents.
frontend/services/a2aService.ts	Adds timeout_seconds to external agent types and a updateAgentSettings API call.
frontend/app/[locale]/agents/components/a2a/A2AAgentDiscoveryModal.tsx	Adds timeout input to the agent settings popover and saves timeout via the new API.
deploy/sql/migrations/v2.3.0_0702_add_a2a_call_settings.sql	Adds timeout_seconds column (default 300) to external agent table.
backend/services/a2a_client_service.py	Reads stored timeout and passes it into A2AHttpClient for normal and streaming calls; adds service method to update settings.
backend/database/db_models.py	Adds timeout_seconds column to A2AExternalAgent ORM model.
backend/database/a2a_agent_db.py	Plumbs timeout_seconds through agent serialization and adds DB update/validation for call settings.
backend/apps/a2a_client_app.py	Adds request model + PUT /agents/{id}/settings endpoint for updating call settings.
backend/agents/create_agent_info.py	Uses stored timeout_seconds when building external agent config (timeout).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.