refactor(workspace): standardize resource settings controls

[Loosand]

What changed

• Replace ad-hoc workspace mode controls with a standard RadioGroup.
• Use standard Tabs for Skills and MCP, plus a single-select ToggleGroup for categories.
• Refine the resource drawer hierarchy, status presentation, empty states, and selected counts.
• Keep every original category while adding safe padding so the default category focus ring is not clipped by horizontal overflow.
• Add the required GUI and WebUI translations.

Why

This is a focused UI and accessibility follow-up for Stack-Cairn#317. It keeps the original workspace-resource behavior while making control semantics, keyboard navigation, focus treatment, and visual consistency more predictable.

Impact

The change is limited to the shared workspace resource drawer, three shared UI primitives, and their translations. It is exactly one commit on top of PR Stack-Cairn#317 head 12e28f80.

Validation

• GUI production build passed.
• WebUI production build passed.
• Focused workspace-resource and i18n tests passed: 8/8.
• Biome checks and git diff --check passed.