[joahg]

Linear: AGNTOPS-773

Why

Buzz should unfurl links by default (Joah's call in the plugin bounty thread). A preview reads a page nobody declared ahead of time. Today the only way to do that is spawning curl, which the marketplace link-previews plugin does. curl resolves the name itself, so it can be pointed at private addresses through DNS rebinding.

What

• A new manifest grant, host.publicPages, and a new call, host.readPage(url, { timeoutMs? }).
• The native side reuses public_image's checks. It resolves the name, refuses any non-public address, connects only to the addresses it checked, and allows only port 443, with no proxy and no cookies.
• It follows no redirect. A 3xx returns { status, location }, and the plugin checks the next hop before asking again, exactly as publicImages works.
• It reads at most the page head (512 KiB, stopping at </head> or <body>). It returns only title, description, siteName, image, imageAlt and icon, preferring Open Graph, then Twitter cards, then <title>/description. Entities are decoded, whitespace collapsed and lengths capped. image and icon are absolute HTTPS URLs. The HTML never reaches the plugin.
• Plugin access review discloses the grant ("Contact any public website for link previews") with the same VPN and IP caveats as public images.
• Docs: plugin-architecture.md and plugin-authoring-guide.md.

public_image::request now takes the Accept header, and its error text says "Public host" rather than "Public image host", since pages share it.

Review notes

• src/plugins/api.ts is FOUNDATION. This adds one optional manifest field and changes nothing else.
• The head scanner is small and hand-written, adding no dependency. It skips comments, <script>, <style>, <noscript> and <template>, and stops at </head>/<body>.

Testing

• cargo test --manifest-path src-tauri/Cargo.toml --lib host_request: 49 passed. That includes 9 new public_page tests: preview precedence, scripts and comments skipped, HTTPS-only URLs, length caps, broken markup, a page answered as fields only through the pinned address, redirect handoff, other types and errors returned bare, and the head limit.
• cargo test -p buzzodz-plugins --lib: 84 passed, including manifest round-trip and rejection for publicPages.
• vitest: src/features/host/service.test.ts and src/app/PluginAccessReview.test.tsx (102 passed); src/plugins/author.test.mjs passed.
• tsc --noEmit is clean.

Part of a stack:

1. This PR: page reads.
2. The link preview slot.
3. Bundled buzz.link-previews, on by default.

🤖 Generated with Claude Code