The aura-2-en model enforces a hard 2 000-character limit per request.
Chapters routinely exceed this, producing 413 errors.
GenerateAudio now splits the stripped text into ≤1 800-char chunks at
paragraph → sentence → space → hard-cut boundaries, calls the API once
per chunk, and concatenates the MP3 frames. Callers (runner, streaming
handler) are unchanged. StreamAudioMP3/WAV inherit the fix automatically
since they delegate to GenerateAudio.
Adds backend handlers and SvelteKit UI for an admin text generation tool.
The tool lets admins propose and apply AI-generated chapter titles and book
descriptions using Cloudflare Workers AI (12 LLM models, model selector shared
across both tabs).
