Feat[Experiment]: Add AI-Powered Content Translation

[yogeshbhutkar]

What, Why, and How?

Closes #187

This PR adds a new Content Translation experiment that lets users translate post content directly from the editor. It introduces a backend ability, ai/content-translation, to achieve this.

The feature is needed so editors can generate translations without leaving the post editing flow. It supports common target languages, gates access through the experiment settings, checks provider support for text generation, validates the selected language, and requires the user to have edit permissions for the post being translated.

Future explorations:

• Add a dedicated action for translating the post title independently.
• Add per-block translation controls through the Content Resize toolbar.
• Extend the support to multiple content blocks.

Use of AI Tools

AI assistance: Yes
Tool(s): Codex
Model(s): GPT-5.5
Used for: Test suggestions and frequent AI-assisted code reviews.

Testing Instructions

1. Enable the Content Translation experiment in Settings > AI.
2. Confirm that an AI Connector with text generation support is configured.
3. Create or open a post that contains translatable paragraph or heading content.
4. In the post sidebar, click Generate Translation, choose a target language, and start the translation.
5. Verify that the translated content is applied to the expected blocks.

Screencast

screencast.mov

Changelog Entry

Added - AI-Powered Content Translation