[pmwoz]

Stacked on #70, which pins the T3 contract that adds path to html_preview and html_render. Merge #70 first.

The Visuals item in skills/poteto-mode/references/t3-adapter.md now says:

• Write the page as an .html file in the work dir and pass its absolute path as path to html_preview and html_render, so the agent does not retype the page in each call.
• Only a full-access thread may pass path. Any other thread gets a capability error and passes the page as inline html.

This follows T3's html handler at 09a54f0 (html/handlers.ts): a call passes exactly one of html or path, and path fails with capability_denied unless the caller's runtime mode is full-access.

Bumps the version to 0.13.8.

Checks

bun run check, bun test tools (39 pass), and bun run typecheck pass.