fix: keep watch dispatch from stealing the visible workspace

[leynier]

Summary

Watch and Fix follow-up injects were calling selectWorkspaceTab, which switched the visible workspace whenever the watched workspace was not already selected.

Background dispatch now writes the prompt to the agent PTY without changing activeWorkspaceId, the active tab, or the panel. User-initiated send (first Watch start, Fix Failed Checks, Restack, file comments) can still focus the agent tab if that workspace is already visible, and does not switch workspaces if the user has navigated away. Opening a new profile tab from a background watch persists the tab without selecting it. Toasts are unchanged.

Mobile comment send still does not auto-navigate. The SnackBar Open action remains opt-in.

Validation

• flutter test test/unit/agent_task_dispatch_test.dart test/unit/agent_task_dispatch_focus_test.dart test/unit/pull_request_agent_watch_test.dart test/unit/workbench_layout_test.dart
• flutter test test/workspace_agent_comments_test.dart from mobile/
• dart analyze on the edited desktop dispatch, watch, and workbench files

Risks

• A Watch follow-up while looking at the watched workspace no longer jumps to the agent tab. The prompt still arrives; the user has to open that tab themselves.
• If the original agent tab is gone, a background follow-up still opens a profile tab in the background. That tab is persisted but not focused.

[pullfrog]

✅ No new issues found.

Reviewed changes Background Watch/Fix injects no longer call selectWorkspaceTab, so they cannot switch the visible workspace, tab, or panel.

• Activate gate - agentTaskDispatchShouldActivate requires both activate and a matching activeWorkspaceId, so a user-initiated send still focuses the agent tab only while that workspace is already visible.
• Workbench persist-without-select - openPersistedWorkspaceTab(activate: false) still adds the tab and skips selectWorkspaceTab; addTabToGroup keeps the current active tab and group.
• Watch follow-ups - timer/onPanelState _dispatch passes activate: false; new profile tabs persist in the background. Prompt delivery stays on the PTY/launchAgent path, not UI focus.
• Tests and policy - service and layout tests cover the gate; AGENTS.md records the no-navigation rule. Mobile comment send remains opt-in Open.

  ^{｜ View workflow run ｜ Using Grok ｜ 𝕏}