dsh-ux: Experience Enhancement Suite for DSH Web Interface

dsh-ux is an independent (unofficial) DSH extension suite, licensed under MIT, that includes the `dsh-enhance` Web plugin and the `dsh-desktop` shell. The `dsh-enhance` plugin optimizes the DSH Web experience by applying a Solarized Light theme with a compact layout, prioritizing the Maple Mono font, aggregating thinking blocks and tool calls into clickable, expandable collapsible capsules, and displaying account balance, token costs, and a 30-day usage chart at the bottom of the interface (requires configuring `DEEPSEEK_API_KEY`). The `dsh-desktop` provides a borderless, immersive window for macOS and supports double-click launching. Users need to install the plugin via the `dsh plugin` command based on `web`.