fix(docs): remove draft content announcement banner (#825)

Removed the persistent "Draft Content" announcement banner from the
Docusaurus documentation site. The banner warned visitors that content
is preliminary, but is no longer needed as the site matures.

## Description

The Docusaurus site displayed a non-closeable announcement bar across
every page with a yellow "Draft Content" warning. This PR removed the
banner configuration and its associated styling.

- Removed the **announcementBar** configuration block from
*docs/docusaurus/docusaurus.config.js*, which rendered the persistent
yellow warning banner
- Removed the **dark-mode CSS override** from
*docs/docusaurus/src/css/custom.css* that adjusted announcement bar
colors for dark theme (now dead code without the config)

## Related Issue(s)

Fixes #824

## Type of Change

Select all that apply:

**Code & Documentation:**

* [ ] Bug fix (non-breaking change fixing an issue)
* [ ] New feature (non-breaking change adding functionality)
* [ ] Breaking change (fix or feature causing existing functionality to
change)
* [x] Documentation update

**Infrastructure & Configuration:**

* [ ] GitHub Actions workflow
* [ ] Linting configuration (markdown, PowerShell, etc.)
* [ ] Security configuration
* [ ] DevContainer configuration
* [ ] Dependency update

**AI Artifacts:**

* [ ] Reviewed contribution with `prompt-builder` agent and addressed
all feedback
* [ ] Copilot instructions (`.github/instructions/*.instructions.md`)
* [ ] Copilot prompt (`.github/prompts/*.prompt.md`)
* [ ] Copilot agent (`.github/agents/*.agent.md`)
* [ ] Copilot skill (`.github/skills/*/SKILL.md`)

> **Note for AI Artifact Contributors**:
>
> * **Agents**: Research, indexing/referencing other project (using
standard VS Code GitHub Copilot/MCP tools), planning, and general
implementation agents likely already exist. Review `.github/agents/`
before creating new ones.
> * **Skills**: Must include both bash and PowerShell scripts. See
[Skills](../docs/contributing/skills.md).
> * **Model Versions**: Only contributions targeting the **latest
Anthropic and OpenAI models** will be accepted. Older model versions
(e.g., GPT-3.5, Claude 3) will be rejected.
> * See [Agents Not
Accepted](../docs/contributing/custom-agents.md#agents-not-accepted) and
[Model Version
Requirements](../docs/contributing/ai-artifacts-common.md#model-version-requirements).

**Other:**

* [ ] Script/automation (`.ps1`, `.sh`, `.py`)
* [ ] Other (please describe):

## Sample Prompts (for AI Artifact Contributions)

<!-- Not applicable -->

## Testing

Verified the Docusaurus configuration remains valid after removing the
announcement bar block. No runtime dependencies on the announcement bar
exist in the codebase.

## Checklist

### Required Checks

* [x] Documentation is updated (if applicable)
* [x] Files follow existing naming conventions
* [x] Changes are backwards compatible (if applicable)
* [ ] Tests added for new functionality (if applicable)

### AI Artifact Contributions

<!-- Not applicable -->

### Required Automated Checks

The following validation commands must pass before merging:

* [x] Markdown linting: `npm run lint:md`
* [x] Spell checking: `npm run spell-check`
* [x] Frontmatter validation: `npm run lint:frontmatter`
* [x] Skill structure validation: `npm run validate:skills`
* [x] Link validation: `npm run lint:md-links`
* [x] PowerShell analysis: `npm run lint:ps`

Co-authored-by: Bill Berry <wbery@microsoft.com>

Author: WilliamBerryiii

docs/docusaurus/docusaurus.config.js

@@ -68,13 +68,6 @@ const config = {
     /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
     ({
       image: 'img/microsoft-logo.svg',
-      announcementBar: {
-        id: 'draft_notice',
-        content: '⚠️ <strong>Draft Content</strong> — This documentation site is under active development. Content is preliminary and subject to change.',
-        backgroundColor: '#fff3cd',
-        textColor: '#664d03',
-        isCloseable: false,
-      },
       colorMode: {
         respectPrefersColorScheme: true,
       },

docs/docusaurus/src/css/custom.css

@@ -65,12 +65,6 @@
   --ms-learn-danger: #bc2f32;
 }
 
-/* Announcement bar dark mode */
-[data-theme='dark'] div[class*="announcementBar"] {
-  background-color: #332b00;
-  color: #ffd54f;
-}
-
 /* Link hover: MS Learn style (darker color + underline) */
 a:hover {
   color: var(--ifm-color-primary-dark);