Add component fixture rendering controls

[hediet]

Adds explicit Component Explorer controls for fixture rendering without changing screenshot defaults.

• Declares toolbar toggles for normal/reversed stylesheet order and CSS animations
• Keeps animations disabled by default
• Splits ranged stylesheet reversal into reverseStylesheetsRange so the Explorer does not need to render a union input
• Updates the scheduled CSS order scanner's bisection probes to use the range input
• Supports shared live controls when multiple theme variants are mounted

Validation:

• Component Explorer Playwright tests: 13 passed
• Ranged render through Component Explorer CLI: passed
• Pre-commit hygiene: passed
• npm run typecheck-client: blocked by pre-existing AuthenticationResponseDetails.firstAuthAttempt error in src/vs/platform/native/electron-main/auth.ts

[Copilot]

Pull request overview

Adds live Component Explorer rendering controls while preserving screenshot defaults.

Changes:

• Adds stylesheet-order and animation toolbar controls.
• Supports concurrent themed fixtures with shared stylesheet overrides.
• Moves ranged reversal to reverseStylesheetsRange and updates scanner probes.

Show a summary per file

File	Description
test/componentFixtures/cssOrderShared.mts	Uses the new ranged-reversal input.
src/vs/workbench/test/browser/componentFixtures/fixtureUtilsCss.ts	Supports stacked stylesheet overrides.
src/vs/workbench/test/browser/componentFixtures/fixtureUtils.ts	Defines controls and applies live input updates.

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 0
• Review effort level: Balanced