Add CNAME file at repository root for GitHub Pages custom domain configuration

[Copilot]

This PR adds a CNAME file at the repository root to configure the custom domain sakurity.tech for GitHub Pages hosting.

Background

For GitHub Pages to properly serve a custom domain with HTTPS support, a CNAME file containing the exact domain name must exist at the root of the published branch. While the repository already had a CNAME file in website/static/ for the SvelteKit build process, GitHub Pages requires the file to be present at the repository root level.

Changes

• Added: CNAME file at repository root
• Content: sakurity.tech (exact domain, no protocol, no extra whitespace)
• Purpose: Enables GitHub Pages custom domain configuration and HTTPS certificate issuance

Impact

Once this PR is merged:

1. GitHub Pages will recognize sakurity.tech as the custom domain
2. SSL certificate issuance can be enabled in repository Settings > Pages
3. The site will be accessible at the custom domain with HTTPS support

This is a content-only change with no impact on the existing SvelteKit application or deployment process.

This pull request was created as a result of the following prompt from Copilot chat.

Add a new file named CNAME at the repository root to configure the GitHub Pages custom domain.

Context / Goal:
The site hosted from this repository (sakuraforge/sakura-forge-website) should serve at the custom domain sakurity.tech. For GitHub Pages to issue and enforce HTTPS for the custom domain, a CNAME file with the exact domain (no protocol, no trailing spaces) must exist at the root of the published branch (main).

Required Change:

• Create a file: CNAME (no extension) in the repository root.
• File content (single line, no newline padding needed beyond standard end-of-line):
  sakurity.tech

Acceptance Criteria:

• Pull request adds the CNAME file at the root.
• Content exactly matches "sakurity.tech" (case-insensitive but use lower-case) with no extra whitespace.
• No other unrelated changes.

After Merge (informational, no automation required here):

• Go to Settings > Pages and confirm the custom domain shows sakurity.tech.
• Wait for certificate issuance, then enable "Enforce HTTPS".

No code build changes required. This is a content-only addition.

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