Kaia Planet Copy v0.1.0

Purpose
- Adds a copy button automatically to existing and future WordPress posts/pages when viewed as a single page.
- Does not modify stored post/page content.
- Copies the page title and rendered post content in Markdown-like plain text.
- Preserves common headings, paragraphs, lists, links, emphasis, code, blockquotes, and image URLs where possible.

Scope v0.1.0
- Posts: enabled automatically.
- Pages: enabled automatically.
- No settings screen.
- No per-post opt-in.
- Button appears before the content at the left side.
- Clipboard success label: コピーしました★

Removal
- Deactivate the plugin. The buttons disappear; stored article/page content is unchanged.
