V161 — AI Post Generator (text only)

Based directly on V160 English-only.

Added:
- /ai-posts: generate 3/5/10/15/20 fresh text posts from one original post.
- Styles: Marketing, Friendly, Professional, Egyptian Arabic, Creative.
- Length: Short, Medium, Long.
- Copy individual / Copy All.
- Per-user saved generation history.
- /ai-settings for admins to store the Gemini API key and model.
- Uses Gemini text generation only; no image generation.
- Root .htaccess routes added.
- Existing Facebook/campaign/subscriber/utility/earn-money modules are otherwise untouched.

Free testing:
Google currently provides a Gemini API Free tier for selected models. Create an API key in Google AI Studio, put it in AI Settings, and test.
