Add Color Picker documentation and samples

[simeonoff]

Task type

• New topic / component documentation
• Update existing topic (new release, API change, new feature)
• Add missing platform variant (Angular / React / WebComponents / Blazor)
• Improve existing content (clarity, examples, structure)
• Add or update code samples
• Other

Platform(s)

• Angular
• React
• WebComponents
• Blazor
• All platforms

Description

Add documentation and live samples for the new Ignite UI for Web Components Color Picker, IgcColorPickerComponent / <igc-color-picker>, introduced in igniteui-webcomponents 7.3.0.

Create a Web Components topic under Data Entry & Display that covers:

• installation, component registration, and basic value binding;
• the default and input modes;
• HEX, RGB, and HSL formats, including alpha-channel support;
• predefined swatches, copy-to-clipboard, and the browser-dependent EyeDropper integration;
• igcInput, igcChange, and open/close lifecycle events;
• form participation, required/invalid/disabled states, helper text, and validation slots;
• styling through the exposed CSS parts and the component's theme/sizing APIs.

Add corresponding runnable samples to IgniteUI/igniteui-wc-examples and embed them in the topic. The sample set should include an overview plus focused examples for the key configuration options and styling.

Acceptance criteria

• A new Platform Color Picker overview topic is added to the xplat documentation with complete SEO/LLM frontmatter.
• The topic is visible for all supported platforms in the Data Entry & Display navigation and is marked as new.
• Getting Started shows installation, import/registration, and minimal <igc-color-picker> usage.
• The topic documents modes, formats, alpha, swatches, events, form validation, accessibility/browser considerations, and styling.
• Runnable Platform samples are added to IgniteUI/igniteui-wc-examples (et. al), including an overview and examples that demonstrate the documented configuration and styling features.
• Every embedded sample loads successfully in the Web Components docs and its source can be opened in the live editor.
• API links/references resolve to platform component and its public members/events.
• Platform documentation generation/build, Markdown linting, spellcheck, and link checks pass.

Related resources

• Component implementation: feat: Added color picker component igniteui-webcomponents#1973
• Component source: https://github.com/IgniteUI/igniteui-webcomponents/blob/master/src/components/color-picker/color-picker.ts
• Storybook examples source: https://github.com/IgniteUI/igniteui-webcomponents/blob/master/stories/color-picker.stories.ts