Update Chrome Web Store listing for freemium disclosure

[PAMulligan]

Description

Update the Chrome Web Store listing to reflect the freemium model. Make clear it offers a free tier and a paid Pro upgrade, what each includes, and update screenshots, description, and the required privacy disclosures.

Why

The Chrome Web Store program policies require honest, non-deceptive listings and accurate disclosure of paid features and data handling. Since Google no longer processes payments for extensions, the listing must set expectations that Pro is billed through us (Stripe), not the store. Getting this right avoids review rejection, takedowns, and user confusion.

Acceptance Criteria

• Listing description states free tier plus paid Pro and what each includes
• Disclosure that Pro is billed externally via Stripe, not the Chrome Web Store
• Screenshots refreshed to show current Optia UI, including an upgrade/Pro surface
• Data safety/privacy fields completed accurately (what is sent to the backend and OpenAI)
• Permissions justification updated if host/network use changed
• Single purpose and policy compliance re-reviewed against current program policies
• Listing links point to the Optia site, docs, and support, not legacy URLs
• CI passes

Resources

• Listing rename/migration is noted as a manual, owner-only step in the repo README
• Chrome Web Store program policies and data safety guidance