[kev1n77]

Summary

Creating an external ACP conversation closes the menu and waits for the agent process to initialize before opening a session. Its lifecycle was recorded as silent notifications, so both the wait and startup failures could look like a failed click. Show persistent startup feedback with a spinner, expose the actual failure with a retry action, and coalesce duplicate creation requests within the same device activation and workspace.

Share the initial model/options and slash-command metadata read on newer hosts. This removes a duplicate RPC and metadata drain during concurrent first-load requests. Add phase timing logs for persistence, transport startup, initialize, session setup and metadata loading; no end-to-end latency reduction has been measured.

Type and Areas

Type: bug fix / UI / performance

Areas: Web UI ACP lifecycle, ACP client metadata response and diagnostics, locales, focused tests and verification guides.

Motivation / Impact

• Startup remains visible before a session tab exists, followed by a distinct session-initialization message.
• Failed creation or initialization shows the underlying error and supports retry. Command lists recover when metadata initialization is retried.
• Request identities include the device activation, workspace and agent. Switching devices or closing a session view removes stale feedback and prevents late results from updating another view.
• A completed metadata snapshot is not cached. The additive optional availableCommands field advertises combined-read support; older hosts retain the commands endpoint fallback, including when the combined result is an empty list.

Verification

After rebasing onto upstream/main at 6518444112:

• pnpm run lint:web — passed, 0 errors (18 existing warnings).

• node scripts/run-vitest.mjs run --maxWorkers=50% src/flow_chat/components/ModelSelectorAcpMode.test.tsx src/app/layout/AcpSessionNotifications.test.tsx src/flow_chat/hooks/useAcpSlashCommands.test.ts (from src/web-ui) — 42 tests passed, including same-device reactivation and cross-device stale-result protection.

• pnpm --dir src/web-ui run test:run src/app/layout/AcpSessionNotifications.test.tsx src/flow_chat/services/FlowChatManager.test.ts src/infrastructure/api/service-api/ACPClientAPI.test.ts src/flow_chat/components/ModelSelectorAcpMode.test.tsx src/flow_chat/hooks/useAcpSlashCommands.test.ts src/app/layout/WindowResizeLayout.test.tsx — 6 files, 100 tests passed.

• pnpm run i18n:audit — passed with zero warnings.

• git diff --check upstream/main...HEAD — passed.

• pnpm run check:web — blocked by four existing typography violations in DeviceWorkspaceSections.scss and SceneBar.scss. Both files are identical to upstream/main and outside this PR.

• pnpm --dir src/web-ui exec tsc --noEmit --pretty false — blocked by three existing missing @/generated/api diagnostics in websocket-adapter.ts and ConfigAPI.ts.

• cargo test -p openbitfun-acp --no-default-features --features client,openbitfun-core/git --lib client::session_options::tests — 10 tests passed before rebase, including legacy payload round-trip coverage. The post-rebase rerun was stopped while waiting for the build lock held by an active desktop development build; that development process was left running.

Reviewer Notes

The single change commit is rebased onto current upstream/main. Conflict resolution retains main's WindowResizeLayout and its updated session-tab guide alongside the ACP changes.

DOM/API fixtures cover delayed startup, errors, retry, duplicate creation, old-host responses and simulated SSH/Peer identities. Native WebView rendering, live provider cold-start timing, and live Remote Workspace, Remote Control, Peer Device Mode and Detached Dispatch scenarios have not been exercised. Existing remote command capability declarations remain unchanged.

No persisted session/config migration is required; rollback is a normal revert. English, Simplified Chinese and Traditional Chinese strings are included.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.