TUI: generic plugin tools don't show their live title while running

Problem

A plugin tool can report progress with ctx.metadata({ title }) while it runs. The TUI only renders that state.title for task sub-tools. For any other tool coming from a plugin, GenericTool (packages/tui/src/routes/session/index.tsx) always shows the tool name plus its input, so the row stays frozen on something like ⚙ my_tool [arg=…] for the whole run even though the plugin keeps updating the title.

Expected

While a generic tool is running and has a state.title, show that title (as Task already does); fall back to the input when there is none. Completed tools are unaffected.

Repro

1. Write a plugin tool that calls ctx.metadata({ title: "step 1/3" }), then later ctx.metadata({ title: "step 2/3" }), during a multi-second execute.
2. Run it from the TUI.
3. The row never changes until the tool completes.

Notes

Six-line change in GenericTool; I have it ready and will open a PR referencing this issue.

Read GenericTool in packages/tui/src/routes/session/index.tsx and compare its running-state display with the Task sub-tool. Ensure a running generic tool shows state.title when available and otherwise retains its input display; completed tools should remain unchanged.