feat(tui): add interactive toast actions - #42407

What

TUI toasts now pause while hovered and use the whole card as a single click target:

• actionable toasts dismiss and run their action
• ordinary toasts dismiss without another effect
• notifications arriving during a hover wait instead of replacing what the user is reading
• plugin and MCP failures link directly to their existing management dialogs

The header shows the destination subtly at rest and highlights the whole-card action on hover.

How

• packages/tui/src/ui/toast.tsx tracks remaining timeout duration, pauses/resumes it across hover, queues notifications while a toast is held, and activates or dismisses on click.
• packages/tui/src/plugin/context.tsx dispatches plugins.list from plugin failure toasts.
• packages/tui/src/app.tsx dispatches mcp.list from failed and unauthenticated MCP toasts.
• Focused provider tests cover action activation, queued progression, and plain dismissal.

Scope

Actions are local TUI callbacks. This does not add arbitrary plugin-defined actions or change the public toast protocol.

Testing

• bun typecheck from packages/tui
• bun run test test/cli/tui/toast.test.tsx test/plugin-hot-reload.test.tsx from packages/tui (9 passed)
• Push hook workspace typecheck (34 packages passed)
• Live bun run dev:live verification with a real failed plugin: hover kept the toast visible beyond five seconds, and clicking opened Plugins

Demo

The recording uses a real plugin failure in the live V2 TUI. The first segment is accelerated while the pointer holds the toast beyond its timeout.

Flow

flowchart TD
  A[Toast appears] --> B{Pointer enters?}
  B -- no --> C[Timer expires]
  C --> D[Dismiss]
  B -- yes --> E[Pause remaining time]
  E --> F{Card clicked?}
  F -- actionable --> G[Dismiss and run action]
  F -- ordinary --> D
  F -- no, pointer leaves --> H[Resume remaining time]
  H --> C
  E --> I[New toast arrives]
  I --> J[Queue behind held toast]