[Feature] Add dummy text generator

[yeleepark]

Summary

Add a dummy text generator for creating placeholder copy that can be used in mockups, layouts, prototypes, and content tests.

Why

Placeholder text is frequently needed while designing pages, testing layouts, preparing documents, or building UI mockups. This fits oddkit's practical toolbox direction and pairs naturally with the existing dummy image generator.

Proposed scope

• Generate placeholder text by paragraphs, sentences, words, or characters
• Support common styles such as lorem ipsum, plain business copy, and short UI labels
• Let users choose the amount of text to generate
• Provide quick presets for headline, paragraph, card copy, and long-form content
• Copy generated text to the clipboard
• Process everything locally in the browser

UX notes

• Keep generation controls compact and the output easy to select or copy
• Use mono labels for count, mode, and preset controls
• Suggested microcopy: // words that mind their own business

Acceptance criteria

• Users can generate text in multiple lengths and formats
• Generated output updates reliably when settings change
• Output can be copied to the clipboard
• No generated or pasted text is uploaded to a server