* feat: add resizable panes to workspace

Added the ability to resize the 4 workspace panes (server, client, flight, preview) by dragging the dividers between them.

Features:

- Drag any edge to resize horizontally or vertically

- Drag the center intersection to resize both directions at once

- Double-click any handle to reset to 50/50 split

- Panes are constrained to 20-80% to prevent collapsing

- Includes keyboard accessibility (tab focus, proper ARIA roles)

* fix: add touch support for mobile devices

Added touch event handlers (touchstart, touchmove, touchend) so resizable panes work on mobile/tablet.

Also increased handle hit targets on touch devices using pointer: coarse media query.

* slightly simplify resizing

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Co-authored-by: Dan Abramov <dan.abramov@gmail.com>

closes https://github.com/gaearon/rscexplorer/pull/6

Co-authored-by: Michael Chen <mchen@ixl.com>

reworks how we handle streams so that they're actually streamy

fixes https://github.com/gaearon/rscexplorer/issues/7

simpler to understand though not as wow

border-radius inside the frame doesn't look good if someone puts a border or border-radius outside the frame.

This fixes this artifact on overreacted:

<img width="222" height="226" alt="Image" src="https://github.com/user-attachments/assets/2675b575-de0c-4227-9aed-50b9eee490e7" />

some of these might have better solutions

Adds explicit styling for select option elements to match the dark theme.
Options were only visible on hover due to browser default styles.