fix(web): make trajectory details panel resizable

[ericleepi314]

All Submissions

Notify authors: @agentforce314, @ericleepi314

New Feature Submissions

• Explained what changes and why it is needed.

Description

The trajectory inspector was fixed at 320px, making long tool arguments and results difficult to inspect. Add a draggable divider on its left edge and remember the chosen width across record changes, closing/reopening, and page reloads. The inspector fits within the available space when the window narrows and restores the preferred width when space returns.

The divider also supports arrow-key resizing and double-click reset. Resize updates stay within the split container so they do not rerender the ledger or inspector content on every pointer move.

Validation:

• cd ui-web && npm run check — TypeScript and the full web test suite passed, including drag completion/cancellation, persistence, bounds, keyboard controls, and render isolation.
• cd ui-web && npm run build — passed.
• Chrome against the local web UI with a mocked gateway — verified actual pointer resizing in both directions, close/reopen, reload persistence, narrower viewport bounds and restoration, keyboard controls, reset, and no browser errors.